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73-87 Chevy _ GMC Trucks => Members Rides => Topic started by: nbarr7 on November 22, 2021, 01:07:04 PM
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Greetings all.
A brief backstory, if I may. I didn't grow up working on engines. My family and my proclivities at the time let me in other directions and helped me gain expertise in other areas. Fast forward to my middle years here, and I'm finding engine work terribly interesting, and yet I realize I'm working from a deficit of understanding and experience. To begin addressing this lack, I started out repairing some jet skis since they're so simple relatively speaking - things like replacing burned down pistons, rings, starters, rebuilding carbs, gaskets etc. It seems like all mechanic roads lead to vehicles for the road, so of course, eventually I followed the momentum of this interest and found a 1987 Chevrolet Silverado (tbi) 4x4 V10 with a 305/auto here in Minnesota that had been sitting for a few years (last oil change sticker was 2016) that was not running at the time due to a fuel delivery issue. "Ok great," I thought "I can figure that out." Well, I ended up just putting essentially a new fuel system in the right side (has dual tanks) so the RH side has a new tank, new pump, new in-tank sock, new sending unit, new soft lines from there to the selector valve, new in-line filter, and I cleaned out the hard lines and the tbi throttle body. So far so good. Here's a video of how it went once I got all that done and added 4-5 gallons (please note the truck has both manifolds both running into a single glass pack, then splitting to those tiny pipes under the bumper - so it will sound consistent with that)
https://youtu.be/xOM2q9UARco (https://youtu.be/xOM2q9UARco)
One of the other fun elements is that the previous owner - for whatever reason - completely disassembled the dash. I haven't looked into the electrical side yet, but I've done some other electrical work so I think I can figure some of it out when the time comes, but I did find the main plug on the back of the gauge cluster was unplugged. Plugged it back in, and to my dismay my oil pressure gauge is either broken, the sending unit is broken, or I don't have oil pressure. I don't hear a lot of valve train noise, but I still am not really driving it anywhere yet until I get an oil pressure tester (on order). Just a couple comments/pseudo questions:
Any advise regarding the possibility of no oil pressure? Getting a testing kit all I need to do to trouble shoot? Also, you can see it does start to smoke a bit a little bit after startup (around the time I go around the big boat in the video). It doesn't smell like coolant to me, but I do have coolant leaving the system somewhere (I'll probably have to get a pressure tester for that too). I did a spot check of cylinder compression to see if the engine was worn out and burning oil because of worn out rings, but I got 140psi. I know I need to check them all, but if I have one or two with good pressure, it should mean the entire motor isn't just worn out I'd think... Mileage on the odo is something like 80k, but of course I'm not sure this is the original dash cluster (it came with a spare for example) and not sure if that's 180 (likely).
I should say that the old oil is full, but dark. I'm planning on changing it but didn't think that would make the difference for the gauge showing literally zero.
End goal is not a show truck, or anything, but I'd like it to be mechanically sound as a warmer weather daily driver type (I'll be getting some body panels eventually if I can get the mechanicals nailed down) Basically, just looking for a community to help me make sure I don't blow anything up or go about this the totally wrong way. Thank you all for your help in encouraging my mid-life personal interest redirect.
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Not a bad looking truck!
I can try to answer a few questions and there are a few others on this forum that are really good.
1) Oil pressure: Ensure your oil pressure sender just above the oil filter is connected (2 Wire connector). Then ensure your oil pressure switch on the top rear (by firewall that has a single wire connector) is hooked up. I would recommend changing the oil first thing, if not done since you bought the truck.
When the oil pressure sensor goes bad you normally get inaccurate readings. When readings fall out of designed specs, a warning light is set.
The oil pressure switch either works or not and if not you could have a bad oil pump. On the other hand check your oil level and if your engine is running quietly, you could have a bad oil pressure sending unit, light switch, or oil pressure gauge.
2) Coolant leaving your system: Should be easy to detect because being up north you should have anti-freeze and should be easy to see since it is colored. Only two places the coolant is leaking internal or external. Internal, you will see your oil level increase as it mixes with the oil. External: it will most likely come from the radiator, a coolant hose, a freeze plug rusted out, thermastat housing, or maybe your over fill reservoir.
My Conclusion: If your engine runs quietly, smooth, your oil pressure sender is probably bad. You need to find the coolant leak ASAP.
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One more thing, it could simply be a burned out bulb if you have lights instead of gauges.
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Thanks, I do have a gauge, not a light. At least, I don't have any warning lights coming on, but the gauge hovers just above zero. I checked the 2 prong wire by the filter, and though it doesn't look to be seated well, it's there. And the one by the distributor is hooked up as well.
I do have bright green coolant/antifreeze yep. Being it's outside on a gravel driveway it's a little harder to see, but I don't know I see a lot of leaks. That said, I haven't really run it yet....
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Maybe hooking up a mechanical gauge is a next step. I would want confirmation of good oil pressure before I made any firm decisions.
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She wouldn't make it down the road for long with no oil pressure, and she would be clacking quite loud .
Nice truck, congrats on how far you've taken her.
Let us know what you find out 8)
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Though not as simple as a test gauge, you could also pop a valve cover to see if oil is making it to the rockers.
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Not bad at all for this part of the country! Welcome from SE MN.
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Shifty's suggestion would be is good and removing the valve cover is a very easy way to see how well your oil pump is working.
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Popping the valve cover will also tell if the oil has been changed regularly :o
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If you run it with the cover off, make sure you have the valve adjustment clips on the rockers, they've been known to squirt oil all over the place.
Having said that, guys, we all know it would sound really bad if there were no pressure so I don't know why we are going down this rabbit hole.
At least he will be able to see if it was maintained or abused.
Maintained=clean components under the cover.
Abused=cruddy crap sticking to the components.
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Have to admit, those clips can help prevent a mess if you have good oil pressure. Could be a wire problems as well if your wiring is a mess nbarr7. Believe you said the gauge cluster was disconnected and you had to hook the connector up. Did you find the coolant leak yet?
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Until you put a number on it, it amounts to assumption and unverified opinion(s). Avoid the pitfall of basing your diagnoses on a house of cards, especially for something as fundamental and crucial as oil pressure. Check the oil pressure using a proper test gauge, as you originally intended, so that you have a "known" baseline.
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I called it a rabbit hole for a reason. ::)
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I have an oil pressure test kit on order - hopefully it will arrive next week, though with the way shipping has gone lately, it may be later than that. I will test as soon as is feasible, and in the meantime I'm not driving it - just starting it every so often, and shifting it slightly to not flat spot the tires.
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Good on you man, hope it works out that you O.P. is sufficient to run her.
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Got my tester in finally. Just to make sure, the sender is the unit that comes off the 90 degree piece just to the drivers side kind of underneath the distributor? Can't really tell if it has flat sides for using a wrench, or if you just need to use a tiny oil filter style strap wrench or?
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The dash gauge oil pressure sender will appear like...
(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37117.0;attach=53625;image)
...(although maybe painted black) and is more likely located just above the engine oil filter. On TBI engines the switch located adjacent to the distributor, typically, is a failsafe to power the in-tank fuel pump in the event the fuel pump relay fails.
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Thank you for clarifying. I found the spot, and hooked up my tester, and this is what I'm seeing with the truck running (video link below). Maybe about 33psi with old oil? Also, I was leaking oil at the connection point and when I went to undo the quick connect, it may have come undone a bit, so even this reading may be a little low. But maybe not. This was a cold start, and only running it for a minute due to oil spilling from the port (so much for the o rings that came with the oil tester kit).
https://youtu.be/aYIZ-vtjbeY
My next issue, assuming this is ok, is to find out why I can put 4 gallons in and the truck will run for like 3 minutes, and then run out of gas haha. Twice this has happened, and hitting the tank it sounds fairly empty. Wonder if it's somehow getting returned to the left hand tank or something? (right hand tank is brand new along with the rh pump and strainer and sending unit)
I also have basically no gauges except the amp meter. Looked for the dash ground near the emergency brake, but the old owner messed so much with the wiring I'm not sure where things are.
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Well she's not a flat girl after all! ;)
33-35 seems low, but your oil may be completely spent with little viscosity left. The leaks might have cost you a few pounds, if they were pouring out.
How many miles is on the motor?
Use some motor flush on the current oil, and fill her with single viscosity oil, like 40w or even 50w.
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The odometer says 108, but as the dash was completely disconnected, I have no way of knowing if those miles pertain to this truck. It was recommended to run something like rotella 15w40 by a friend, so I was looking at that 40 weight level anyway.
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Rotella is a good oil. I would start with a single vis oil first.
33 is low for a cold motor. But in this case, you don't know if it's loose bearings or shot-out oil.
If it jumps to 45, with new oil while cold, it means the bearings aren't shot, it will thin out as temp is gained.
If it drops to 30-35 I wouldn't lose sleep.
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Old rule of thumb...10lbs for every 1000 rpm after 30lbs.
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Thanks for the help and opinions. I've removed the oil pressure sender - would you all replace that or just run a mechanical gauge for a while? I have one of those basic 3-pack gauge sets laying around anyway, but my long term goal is to use the in-dash gauge. Not sure how to troubleshoot it if it's not even hooked up...
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Ok here we go. I did change the oil and filter (wix) and went with Rotella 15W40 as it was local, easy to get up here, and another friend runs it in his tbi suburban. I can always go to a straight 40wt later if needed. I installed a mechanical oil gauge for now, since I still have zero dash gauges excepting the amp meter. I'm now showing around 40 shortly after starting (cold) (see attached image)
The truck is still doing this thing where I'll put 4 or so gallons in (have done this twice now) and it will run for maybe 3 minutes, then act like it's out of fuel. It's a new tank, so I know you need a few gallons just to submerge the pump, but I've put 4 gallons in twice at least, so that means there should be 8-10 gallons in a 16 gallon tank which shouldn't run out in 3 minutes. And as a reminder it's a brand new fuel tank, new pump, new sending unit, new in-line filter, I used a dremel/sanding disc and ground a bare spot on the frame to re-ground the sender, and all hard lines have been blown out with an air compressor (except those 'aft' of the filter as I didn't mess with the selector valve yet and didn't want to blow compressed air through that). The throttle body and injector housing has also been disassembled and cleaned out with carb cleaner.
It's really weird. Even if I put fuel in the throttle body, it will only burn that much and then quit like it's empty. But 3 minutes before I had added 4 gallons, you know? Thoughts of what to check next? On either fuel delivery or factory gauge non-function?
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From personal experience, you can keep the engine running on a level surface with just over 1gallon. I would verify the return line routing. Hand over hand this item you'll thank yourself later. Tap the other tank and see if it's full, at this point you should only have to add 4 more gallons and the other tank will likely start to overflow.
The selector valve/switch can leak by but unless the internals are almost missing it wouldn't leak by that much that quick. The valve may have been replaced or at some point the returns swapped. I'll try and find a diagram but for reference the return is the 5/16" hose (the middle size) the smallest is a vent for the charcoal canister (if it still exists) and the larger line 3/8" is the fuel supply.
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Sorry for the delay all - the truck is in my driveway (I don't have heated shop space - only a woodshop) and with temps at or below zero Farenheit, I haven't been able to make myself crawl underneath - my fingers just don't work at that temperature. I'm thinking of bypassing the selector valve for temporary (until spring) just so I know everything is good from the brand new tank, pump, and sending unit to the throttle body etc. We'll see what I can do later this week if/when it warms up.
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I don't blame you one bit. My garage is for tools, not parking vehicle, except maybe 🤔 a motorcycle or two. Way too many tools and parts for anything else.
Down here we've been in the 30-40 at night and 50 to low 60s during the day but that dang wind!!! 😬
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Ok, I took the relative reprieve yesterday of double digits above zero and used double ended barbs to connect the RH tank directly to the send and return lines going to the throttle body. Tapping on the tanks themselves with wrench/stick, the LH tank does indeed sound full, and the RH tank sounds largely empty - must have been pumping fuel to the LH tank as well as a small amount to the throttle body, so that it died in 2 minutes or so.
Fun side note, when I disconnected the RH tank from the selector valve, something in the LH tank was allowing it to act like a little water tower or pressure tank and it started dripping gas slow, but steady for a while out of the selector valve itself. I filled up a whole ice cream bucket with gas dripping while I ran to the parts store to get some vacuum plugs to wire clamp over any fuel selector openings I left open during this process. I didn't think the LH fuel pump would allow fuel to just pass through. Turns out I got to get a free hand/down the arm gas shower instead.
Since yesterday, we're back down to like 3 degrees, so I'm going to wait a few days before trying to start the truck (also hoping some of the gas that got spilled around the ice cream pail gets dried up)
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Well that leaves two options: 1) lines are incorrect.
2) selector valve/switch is leaking by.
If you're not worried about the second tank and just want drive then keep your current set up bypassing the selector and drive to see if there are any other issues. This way when you take it down to fix the fuel tank issue you can fix anything else that come up while it's down.
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So after connecting my brand new RH tank setup directly to the send/return gas lines, I started the truck. I thought instead of typing everything out, I'd just make a quick video of it, that way you all can see what I'm talking about more easily than trying to explain it
https://youtu.be/Q7WcPpBzI2c
-if it's germane in any way, it was brought to my attention that in the oh... 7-8 times I've started it these last 4 months, I've never really driven it over 10 mph, nor revved it above maybe 2-2.5k rpm. I don't think old gunk not being burned would smoke this much at every startup, but hey... there is probably years of crap in there that hasn't truly been blown out.
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Isn't YT great? Thanks for putting that up, it does help to see whats going on.
As far as the steam in the exhaust, it did seem to get better the longer it idles, but in order to flash off all the condensate in the exhaust, it needs to be driven for a while to get the exhaust up to temp. If after that it steams some more, a coolant blow by test would be a good idea. IMO.
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Yes the white smoke is just condensation of water in your exhaust. Normal especially in that cold weather.
When she's up to temp, as in having driven her for 5 miles, you should not see it.
If you do, as wz stated, start looking for the problem. Compression test would be first, at least for me.
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Thanks for allaying fears regarding the smoke. I very much appreciate the expertise here. I am working on another video now that I'm doing test drives down the road - I installed a manual temp gauge finally too. However, the Transmission is acting up, and I don't appear to have atf on the stick at idle in neutral. Do I need to top off with some form of Dextron then? I do have a quart of valvoline dex/merc but not sure if that's right.
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Dexron 1 and 2 were superceded by dex/merc.
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Got it. Ok, well Napa says I need Dex 6, so I'll figure something out and report results this weekend
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Why not change the filter and fluid while you're at it?
Especially if it is brown or smells burned.
Keep them clean and they last a long time... ;D
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Yes, changing filter and fluid was suggested by a friend. I guess my only hesitation is once again, it's below zero degrees Farenheit this morning, and I have to work on it outside as I only have a woodshop at this point. If it warms up, perhaps that's the direction I'll go. Just having a hard time waiting to drive it down the road ha. Napa says Dex 6 is what is listed. Is that what you all would use?
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Dex III/Merc is fine. Dex VI is over double the price, and not necessary for a square,
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It's been a little bit, but with the coming of March in the northland, warmer temperatures and sun have also returned, allowing me to get back to prioritizing the silverado. I had the good fortune to be the recipient of the benevolence of a local mechanic who helped me over a hurdle with a starting issue, and also made actual progress. However, at this point it seems every point of understanding gained comes with another point of the unknown, and my transmission is acting in ways I was not expecting it to act and it is with this in mind I'll provide another video update, vlog style, so you call can see and hear how things are:
https://youtu.be/pt0riMV_JOw
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Watching the video gives me a good bit of insight to your frame of mind. Now I'm not saying it's off but I'd like to point out the white stuff that's everywhere. Sir, that's is not indicative of 'warm weather'.
Glad the engine is running. That temp sensor you put in near the thermostat housing as you stated is very important for the TBI ECM as you now know.
I would speculate that you have a 700-r4 transmission but you need to check to be positive. It's the only way to help you as much as we can.
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Here are some pan images that are the most common. The shapes are what give them away. Sometimes the hardest are distinguishing the modern transmissionsfrom it's grandfather th700-r4 and th400. Close attention to the oil pan is key.
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It appears based on your photos that this is the 700r4, no?
I have always been in 2 high, but realized my front hubs were locked for 4wd - put it in 4hi today to get into the garage (icy driveway for one wheel) and it worked as is. Not sure that makes any difference but it's another point of reference.
I also believe I am missing back brakes. That's obviously further down the road.
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The passenger side (aside from being filthy) does have some wiring that looks... somewhat compromised. Not sure what's what here, but here are photos. It goes without saying I'm not driving the truck right now with the trans like this - only idle speed around my driveway
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Thanks for the pics, there a several shifting issues we can try and address but after seeing those pics there's one specific one lingering in my mind. Where's the trans fluid you were missing? It's obvious that it didn't leak out. I suspect it may have leaked into the transferase. You can verify this by parking on a level surface or jacking the truck up on stands to make it level. Put a catch under the rear of the transferase and take out the fill plug. You will likely get a little fluid out but If it poor's out then the transferase input seal is bad and it explains the loss of fluid without external leakage.
The fear here is the low trans fluid may have burned some clutches or hopefully you just have some stiction issues within the valve body and or governor. As already recommended, get a new filter, gasket and fluid and replace a quart of trans fluid with Lucas trans additive. I have had great success with this. I'm sure there will be other recommendations for you as well.
The hard clunk you experience is often the anti clunk spring. This isn't a simple repair and requires tearing down the transmission and removing the center section. It is a common problem but a small issue compared to everything else right hopefully it is still in one piece and not rubbing on the case.(https://uploads.tapatalk-cdn.com/20220303/1421049a01cf7f492fc8b96760cc8673.jpg)
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The transmission issue was resolved (not by me) and it's a bit embarassing as it was a simple oversight on my part. I'll try to swallow my pride and post about it in the hopes that if anyone else ever has this, they'll learn from my idiocy. Video coming soon.
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Humility takes courage.
Those who are 'never wrong' are weak.
You will be a better man.
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Late March video update on the truck. Progress is being made. Despite my inadvertent attempts to thwart it
https://youtu.be/spD-bltGjqY
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I know it must feel good to drive it, I have not driven mine for years and look forward to to first ride.
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I know it must feel good to drive it, I have not driven mine for years and look forward to to first ride.
Amen, can't wait to have that feeling again!
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New Video update is coming soon with info on timing, replaced ignition parts, and some basic cosmetic work.
In the meantime, I seem to be losing coolant. No smoke at all in the exhaust, so I don't think it's a head gasket. It's in a gravel driveway so leaks are hard to see. Almost seems worse when I drive it, like the transmission is involved or somehow driving it down the road increases the loss. I know I likely need a pressure tester, but wondering if anyone knows any obvious places to look (besides clamps on the upper and lower rad hoses which seem dry - the trans hard lines do seem sort of chewy, but I have to look closer to see if there are any actual holes)
sorry for the delay. Lots of video clips to put into an update soon
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I doubt the trans is involved, as much as driving it builds up heat/pressure by itself.
Place a piece of cardboard under her next time you park.
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...I likely need a pressure tester...
This ^^^^^ Inspect all of the connections you mentioned as well as the radiator core and tank seams. If a leak Is not visually evident under pressure, see how long the cooling system maintains 20 PSI - how quickly it bleeds off. With the cooling system full and the pressure tester fixed in place of the radiator cap, start the engine dead cold to see how quickly cooling system pressure builds from zero to 20 PSI; just don't let it build beyond 20 PSI.
Is there an intermittent "sweet odor" inside the cab? Check the engine oil on the dipstick for water droplets or tan colored mayonnaise. Inspect the weep hole on the water pump neck for coolant tracking. Closely inspect all of the accessible cylinder block welch plugs, including the one hidden behind the starter and the two in the rear of the block behind the flywheel/flexplate. Remove and inspect all of the spark plugs to see whether any are exceptionally clean.
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I got a pressure tester, but have since encountered a rough idle/timing issue, so I haven't prioritized the coolant situation. It does seem to get to about half full in the radiator, and then seems to stay at that level. I don't have sweet odors in the cab nor water droplets in the oil that I can see.
Here's a video that explains some of the updates, but lest this seem like a plug for some youtube show (which it's not - videos are private and just for information on this forum) I'll summarize here:
I took the bed off, and went down and got the frame patched. Because of the faulty selector valve, the left hand tank (which I never used) started gravity pouring gas back to the selector, and actually started the selector valve on fire from welding sparks. So... after some melty wires and fully deleting the selector valve, I'm now running without a left hand tank at all, and just plugged right into the right hand tank with no selector valve - which is currently on the ground until I can drill out the patch panel on my frame and re-hang my gas tank.
The big problem is that somewhere in early spring I started having a high idle that the truck just wouldn't come down off of. We checked for vacuum leaks, re-gasketed the throttle body, replaced the iac valve, and did some timing work. Now here's where things get weird. We may have been unplugging the wrong wire to put the truck into 'base timing" mode and so we thought all the computers were off (in my defense a professional mechanic was with me at this time). To that end I replaced the icm in the distributor, and then when that didn't take the high idle down, I replaced the ecm with a brand new one. Now, I have to admit to stupidity/ignorance (since I was replacing it alone and have never worked on cars before). I unhooked the battery when I put in the new ecm but I didn't know I needed to swap the modules from the old ecm at first. I know I hooked up the battery with modules out - I may have tried to start it that - way it's been so long I can't recall. I finally found online the info that I had to swap the chips/modules, and started the truck and THAT was the moment that it started to run really really rough. Like way out of time and backfiring and everything.Now it seems to not stay at the same timing. And still starts hard and runs weird. I had it timed at almost at zero yesterday, and adjusted the distributor just a little, and then I couldn't even find the timing mark on the harmonic balancer 2 minutes later. Like it's either shifting timing on its own, or... I don't know.
After all that, I also swapped out the spark control computer and map sensor just in case. No change.
Thinking maybe I had fried the ecm by putting power to it without those chips, I went and got a cheap used ecm out of an 88 tbi burb, and it does the same thing. So then I put the old icm back in the distributor, wondering if I had fried that. Same thing. So... Did I smoke a sensor somewhere that's giving the ecm a bad reading? Or would the timing chain just happen to stretch at the exact time I put a new ecm in? I'm really stuck here, and can't really do anything else diagnostic on the truck when it wont' run right. Yes this is likely all my fault, but I know it takes money (and/or time) to "go to school" and I"m ok with that, generally. The point is to learn. I'm just... I'm needing some actual progress here. I feel like after all the work I've done, the truck has just gone backward. The only thing I seem to have done semi-right is the fuel system - which in my defense is what I bought this truck under the assumption that was all it needed. All this (and more) is explained in the May update video linked below:
https://youtu.be/Z8duMLKPOzk (https://youtu.be/Z8duMLKPOzk)
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I most likely can't help much, I know next to nothing about injection systems and sensors. But I would start with the assumption that something in your parts changes may be at fault. I know what I'm saying is pretty basic, but I would start with checking every possible wire for breaks and bad spots. Every connection for loose wires or corrosion, etc. I once walked 3 miles in midsummer heat because my Chevelle had run out of gas - only to find out that the ignition wire on the back of the hei distributor had come loose.
Is it possible that over the winter a mouse has decided to use your harness to snack on?
Good luck!
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STOP throwing parts at it! You'll just burrow into a deeper hole than you're in, already.
The high idle issue probably was the cruise control link that you eventually disconnected. It is a common problem.
Begin by validating the ECM I and ECM B fuses in the fuse box - physically remove and inspect them. Disconnecting battery power from the ECM will clear any stored codes, many of which may be false reads. Next, replace the fuel filter and measure the fuel pressure using a proper test gauge. TBI systems are exceptionally sensitive to fuel pressure.
Fill the cooling system and start the engine. Keep it running for up to a minute and then check the ECM for stored codes and write them down. Use a scanner if you have one, otherwise retrieve the codes manually. Post all of the results.
You really need to determine where the engine coolant is going.
FYI - The ESC timing bypass (for base timing adjustment) is the tan wire with black tracer passing through the single wire Weatherpack connector; see image.
For normal vehicle operation, the ESC bypass should be connected (plugged together). Base timing should be checked and adjusted only with the engine at normal operating temperature and the ESC bypass disconnected. Checking engine timing with the bypass wire connected is a waste of time since timing is controlled by the ECM and could be anywhere, thus appearing erratic.
If you are compelled to validate the timing chain, refer to How to Evaluate an Engine Timing Chain (http://forum.73-87chevytrucks.com/smforum/index.php?topic=35820.msg302304#msg302304) in the Technical Forum.
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My apologies. I'm actually changing some of the new parts back just to eliminate so many variables. Fuses are good - I checked all my fuses yesterday. I will have to buy or rent a fuel pressure gauge. I don't have a scanner, and currently my dash is all wonky since I took my taillights off with the bed (i.e. my check engine light isn't even on at all so I don't think I can manually read codes) I'll also see if someone has an old scanner. Again, sorry for going about this the wrong way - I know throwing parts at things isn't the answer, but many of those parts were recommended by a mechanic, but I think regardless of what he says, I need to sort of start over.
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Scanner can be found at reasonable prices. Having tail lights disconnected/removed should not cause any problems. My electrical system is working OK right now without the bed harness connected to any of my tail lights (my bed is removed right now).
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...my check engine light isn't even on at all so I don't think I can manually read codes...
NO "SERVICE ENGINE SOON" LIGHT -CHART A-1 - (TBI) (http://forum.73-87chevytrucks.com/smforum/index.php?topic=37738.0)
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I discovered that if I hold the light bulb in place with my finger (forcing better contact with my somewhat floppy copper strips) I do indeed have a check engine light that goes off once the vehicle is running. Jumpering the obd port now
*edited because I remembered I caused a code
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Ok. I will post a video later, but my check engine light is on (if I hold it with a finger) before startup, and then goes off during startup. I disconnected the negative side of the battery for over 5 minutes and cleared codes. I then ran the truck for 1-2 minutes. Jumpered the obd port, and my check engine light gives me 1-2 over and over, which I read 12 is the start and end of any code sequence, so unless I have an error code of 12, it's giving me no ecm codes currently. The truck is seeming to run a little better, but still has a weird start.
I'm renting a fuel pressure test kit from O'Reiley's in the morning so I'll let you know what I get for a reading there.
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Just to avoid any misinterpretation (on my part in how I describe things) here's some video clips of how I checked ecm codes and how the truck is currently starting/running. Fuel pressure test coming tomorrow still.
https://youtu.be/s553Rz0etA8 (https://youtu.be/s553Rz0etA8)
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Rented a fuel test kit this morning. The pressure goes up to maybe 10-11 psi when you first turn the key on, but dwindles after the pump shuts off. Pressure goes back up to about 12psi when the truck is running. Seems constant at this pressure. Once truck shuts off and pump is turned off shortly after, pressure drops back to zero. Here's a video showing the process and hearing/seeing it in real time so to speak. I know the gauge is higher than needed, but it's the only kit O'Reiley's had, and living an hour outside of Minneapolis, I only have so many options.
Fuel pressure video from this morning:
https://youtu.be/w8K2AVJL24s
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Code 12 is an ignition "tach" signal code that is normal whenever the ignition is switched ON with the engine not running. It is a volatile code that will not store in memory and does not indicate a problem.
Running TBI fuel pressure should be about 12 PSI. So, the running pressure appears normal, although it should maintain about 7 PSI for several minutes after the ignition is shut OFF, suggesting minor internal leakage through the pressure regulator or fuel pump.
Verify the spark plug wire firing order 1-8-4-3-6-5-7-2. Remove the passenger side spark plugs and keep them sorted in order and labeled from front (cylinder #2) to back (cylinder #8). Make sure none of the ceramic insulators are cracked and then post a clear closeup pic of the electrodes as they were removed from the cylinders.
Wipe the fuel injector tips (nozzles) with a clean rag. Slip a piece of clean, dry paper towel below each injector, directly above the throttle plates, and cycle the ignition key ON and OFF without cranking the engine. This will momentarily energize the fuel pump and build fuel pressure. Inspect the paper towels for wetness to see whether the injectors are dribbling any fuel.
Have you run a cylinder compression or leak-down test?
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Before I saw this reply about testing plugs etc, I had a little bit of downtime at work so I attempted to time the truck.
Please note I have never timed a car, or even held a timing gun until today, so... I'm learning. Bear with me.
The short story is that the timing was way advanced, I believe (?) and I was able to get a stable timing read with the ecm bypass unplugged. I eventually got the timing to what I believe was zero. Low idle, but running smoothly all things considered. I then disconnected the negative terminal on the battery for 15 minutes, reconnected the ecm bypass, reconnected the negative battery terminal, and tried to start the truck. Ran horrible - backfiring and not even staying running. Checked for ecm codes, and still only have 12 over and over. Here's the video:
https://youtu.be/HP39iIEvRzk
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Seeing as how the ignition timing seems all wonky, you should verify that the outer ring of the harmonic balancer hasn't slipped, altering the position of the timing mark with respect to the crankshaft. If the balancer has slipped, you will never get an accurate timing adjustment.
Remove all of the spark plugs, keeping them in order by cylinder number. Bump the engine over using the starter until the #1 cylinder barely begins to build compression. With help from an assistant, bar the engine clockwise by hand (from the perspective of looking at the engine from in front of the radiator) until the #1 piston just reaches its peak upward travel before reversing direction. You can closely approximate piston position either by peering through the spark plug hole as the piston is moving or by feeling the top of the piston using a thin probe inserted through the spark plug hole. Once the piston has exactly peaked in its cylinder, look at the timing marks to determine whether they align at zero - they should. If the marks do not align at zero, the outer ring has slipped to the extent of the visible separation and the balancer should be replaced. There are other methods, but this should work for you in the field; pun intended.
BTW - This does not negate the other checks and procedures recommended thus far.
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Not so frozen now we see... ;D
bd is right, check that you have a stable balancer before anything else.
If you're off mechanically you will be chasing the wind.
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I will recruit my wife to help this weekend with checking the harmonic balancer positioning relative to tdc.
In the interim, I am addressing some electrical gremlins, since electrical is closer to my comfort zone. My fuel gauge now works (it had never worked since I got the truck) and I realized the issues with the brights indicator being on and my temp and oil pressure gauges suddenly not working was the copper stripping around the back side of the clock side of the dash especially, had gotten somewhat bent from removal/install/removal of the dash cluster (both from previous owner and me) and the ground strip and one other piece were actually severed in one place. So, delicately soldered and checked continuity on those and I have a fully working dash (except the clock is really hard to set since the post/twisty thing is bent and corroded). I even have a dome light suddenly when turning the lights knob all the way counter clockwise!
I've been reading pinout diagrams and wiring charts (what I have access to via google anyway) and am wondering if someone could provide a comprehensive list of where I should have grounds on this vehicle? It's a big ask, so I'll start with what I know, and maybe someone can fill in the blanks...
Battery negative is grounded to the frame, drinker's side engine bay, which is connected then to the alternator bracket. I also have a ground next to the thermostat. I do have continuity between the body and neg/bat, so the body ground appears to be working . I have verified gas tank/fuel pump is grounded in both send/return lines and the separate frame ground. I've found and verified the ground for the dash cluster at the plug as well as the system grounds at A12 and D1 at the ecm plug. I've verified o2 ground at D6 and crank sensor at C9 on the ecm plug. I do NOT have a ground for D2 or "Map Ground" but looking at the wiring diagram, it maybe seems like I shouldn't? I'm basically trying to find if I have a short to ground in any circuit I shouldn't kind of thing. Or vice versa, if something isn't grounding out and not completing the needed circuit. I'm also getting a very small spark when I re-connect the negative to the battery, so something is drawing or grounding.
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All of the GM factory manuals are available in our Technical Forum \ General Information and Maintenance \ 1973-87(91) Factory GM Pickup Manuals (http://forum.73-87chevytrucks.com/smforum/index.php?topic=30115.msg252586#msg252586)
Basics: Vehicle Ground (http://forum.73-87chevytrucks.com/smforum/index.php?topic=35756.msg301879#msg301879) catalogs the major ground points that are shared by all of the 73-87(91) squarebody trucks. For application-specific grounds, you will need to reference the appropriate year factory wiring manual.
Sparking at the battery is common. To determine whether it is significant, measure the current draw using a proper ammeter.
FYI - Ground connections should be validated by voltage drop, not by resistance (continuity) measurements. Even minuscule resistance can prevent the proper functions of moderate to high current circuits (e.g., arbitrarily, greater than ~2 amps). Most ohmmeters are not sufficiently sensitive to accurately measure such small resistance.
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Super helpful. I apologize I didn't find those resources earlier. Google doesn't suggest them as readily as other forums and resources apparently. Thank you.
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In inspecting the harmonic balancer, I found my coolant leak. Unfortunately it looks like it's coming from the bottom of the water pump. I'm assuming that's shot then. Makes sense why I'd lose coolant worse after driving (why I was afraid of a head gasket way forever ago).
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Hello all. While this is NOT the end of the story, I wanted to officially post the process of my fighting with the esc bypass so others can see what I was experiencing.
Synopsis for those not wanting to watch:
After timing the truck as documented in this thread, I tried adjusting timing 10 degrees advanced and retarded to account for any slippage in either direction by the harmonic balancer. Truck ran fine with the ecm bypass disconnected but ran like absolute garbage as soon as that wire was plugged back in regardless of advanced or retarded turning of the distributor. Over and over, no matter what I did truck ran fine in base mode, and basically didn't run (backfiring/rough not staying running) as soon as I tried to get the ecm to control advance. I had my wife help me find tdc, and harmonic balancer didn't seem too off. Based on other forum posts here and other places, people describing the ecm bypass wire issue I was having usually traced it back to some portion of the distributor. So... I took mine out to replace the pickup in there. I disassembled it, and cleaned it, and replaced the pickup and the reluctor (since I broke the reluctor getting the stuck parts apart) and then I had a wonky time getting the distributor to clock right when I reinstalled it - even though the truck had not moved, nor had the engine turned. I still don't actually know what was going on there. So, ultimately I decided to get in-person help and a local mechanic took it to his place to get to the bottom of things. Next update will document that progress, but this is the (late) video update for LAST month.
https://youtu.be/NgPv6_qhlVY (https://youtu.be/NgPv6_qhlVY)
*Be aware I'm not asking for advice for this video, since actually most of this is rectified now -not by me - but that update is to come once I get the truck back.
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Well, we have made progress on the ECM issue. I have a video explaining it, and chronicling the current month progress on my truck.
https://youtu.be/TlnykKS6tSY (https://youtu.be/TlnykKS6tSY)
Note in the video that my local mechanic also had a new bed, so it's now sporting a surface-rust blue box.
Also, it seems like I'm replying to myself mostly on this thread by now, so if this is uninteresting to you all and you have suggestions as to how to make it more engaging, let me know. I don't mean to just take up digital space. Hoping to kind of take you guys with me as I learn, and as this truck gets slowly better and better.
*for the TLDR folks so to speak, to summarize the video, the truck is now home and runs. The ECM issue could have been a few things, but a wire was found to have pulled slightly out of the harness going into the ignition control module. I thought I had checked for shorts in all 4 of those wires but who knows. I very obviously miss things. An entire new distributor was also put in, so that could also have helped as well. Either way, if anyone is having that problem of only running well in base timing mode with the bypass circuit unplugged, it seems to generally be related to the distributor, or wires thereto.
Next up, I'm looking into tires and new springs, and some general bushings and etc to get us riding a little smoother...
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It's been a little bit, but there is progress on the truck. I replaced the water pump (and radiator hoses) and I no longer seem to be losing coolant. I also had a decent fight with one of the rear wheels that was all but welded on with rust/friction, but finally prevailed, and the truck is now sporting some 33" tires I found around here used for cheap. I'd eventually like to re-wrap my rally wheels with beauty rings etc, but for now these work since they came with the rims they're on. So at this point, I believe I have an unequivocally running and driving truck. Which is where I wanted to be a year ago, but I've fixed an awful lot in this past year as well, so I shouldn't complain.
As it's advancing toward winter here in Minnesota, I likely will not do as much on the truck at this point, since I don't plan on driving it winters. That said, one of my next moves is addressing sacked out suspension. I think with these 33s (that somehow don't rub at all currently) I'm going to look at 2" lift springs, and do some shopping for correlating shocks. With this not being a work truck, I wouldn't mind the ride being smooth-ish, and I've heard good things about e-z springs, and I may go that way.
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It's been a, well, a frozen northern winter. Which I love, but having an unheated shop doesn't lend itself to truck progress. With spring tentatively arriving, however, projects once again are underway on the 87. Most recent is an e-z ride based 2" spring lift (blocks in back) to improve ride and look just slightly better. Shock towers were painted black, since we're keeping things simple on this guy. I've never lifted anything, and had a friend help with front disassembly, but kind of just figured things out as I went (and asked friends a LOT of questions). I still need to buy new rear leaf springs as the kit only came with fronts (why I suspect she's down at the rear slightly) but she's ever so slightly coming along...
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Rompin', stompin' Mickey Thompson! 100% would hoon the heck outta that!
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Looks bitchin!
Great stance!
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A hoon is an Australian term describing a person who deliberately drives a vehicle in a reckless or dangerous manner, generally in order to provoke a reaction from onlookers.. Hoon activities (or hooning) can include speeding, burnouts, doughnuts, or screeching tyres. Those commonly identified as being involved in hooning are young and predominantly male drivers in the age range of 17 to 25 years.
Sounds like most of us here, at least at one point in our lives. 8) ;D :o
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Guilty...(except the age bracket) ;)