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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: DnSherrill on September 10, 2018, 12:46:37 PM

Title: newb needs direction
Post by: DnSherrill on September 10, 2018, 12:46:37 PM
1986 C10 5.0L with ESC; all original with rebuilt quadrajet pn 17085226;
recently pulled off  the intake to do some general cleaning and replace gaskets. I'd also like to eliminate the charcoal cannister and smog pump and as many vac lines as I can; vehicle is subject to safety inspections only;
I bought a used alum intake, oem pn 14057053, off a Z28 or Corvette, to replace original steel IM
How much else do I need to replace in this project? go to a HEI vac assisted distributor and a different carb? I haven't checked if my vehicle has an ECM
this is not a performance build; primarily just want to clean up the engine bay
I'm sure there's plenty of write ups on this already, I'm searching for one that applies directly
Title: Re: newb needs direction
Post by: Rapid Roy on September 10, 2018, 01:38:41 PM
Welcome
Title: Re: newb needs direction
Post by: DnSherrill on September 10, 2018, 02:31:16 PM
after just a little bit of research, it looks like eliminating emissions controls, including secondary air pump, just for the sake of cleaning up the engine bay,  would be too much $ for not enough bang
Title: Re: newb needs direction
Post by: DnSherrill on September 10, 2018, 09:08:04 PM
my carb is a Qjet 17085226, type R4-M4MED.......
this is my distributor...is it HEI? CCC or non CCC?
I always thought my truck has ESC, maybe I'm wrong on that
Title: Re: newb needs direction
Post by: VileZambonie on September 11, 2018, 09:05:15 AM
Judging by the wiring there, it looks like someone attempted a bypass and subsequently pinched the wires under the cap. Now's a good time to replace it with a vacuum advance HEI or better. As far as the carburetor goes, unless you plan to keep all of the emissions controls in tact, an upgrade would be in order.
Title: Re: newb needs direction
Post by: DnSherrill on September 11, 2018, 10:52:38 AM
thanks
I checked resistance on those pinched wires.....there's good continuity now, less than 1 ohm on each. The truck runs smooth now, the quad was installed as rebuilt less than 50k miles ago and still starts and idles fine. on this distributor the vac assistance was not connected when i pulled off the intake; I haven't located an ESC module on the firewall. Ideally, I'd remove emissions components without replacing a well functioning carb and ignition system
btw, vin 1GCEC14H7GF301875
Title: 1986 ECM?
Post by: DnSherrill on September 11, 2018, 03:56:10 PM
did some or all 1986 C10s have ECMs?
Title: Re: newb needs direction
Post by: VileZambonie on September 12, 2018, 05:45:21 PM
Okay so your post is confusing and contradictory to me, here is what I get from what you are posting:

You say it's all original but obviously not all original and you want to eliminate anything emissions related that doesn't negate passing a safety inspection although I am not clear why you want to do this since you say it runs just fine and performs as you like. So what exactly is your end goal? To give direction I would say this, pick a goal and work towards that goal, you seem torn between staying stock, not spending a lot of money and wanting outside direction but again, what direction do you want to go?

Based on the components you say you have, yes you have an ECM.
Title: Re: newb needs direction
Post by: DnSherrill on September 13, 2018, 06:50:55 AM
sorry to be all over the place.......
I've had this truck since 2002, but currently drive it on average 15 miles/month...probably 2k miles over the last 5 years
carb is not original, radiator replaced, beyond that all original as far as I know.
ECM? I noticed last night there is no o2 sensor, nor has one been plugged.
well, I started out wanting to resolve oil leak(s) and resolve coolant loss (radiator has been replaced less than 10k miles ago and I see no coolant on the ground) it starts fine, and runs smooth with smooth idle, coolant is bright green and oil looks normal......Replacing head gaskets is not an option currently, I'm thinking I'd need to remove the engine for that project.
 regrettably I neglected to test coolant system pressure or check compression before removing intake manifold. 
so, for now, the goal is fix oil leaks and stop coolant loss, I'd like to delete useless vac tubes and emissions components.
Title: Re: newb needs direction
Post by: VileZambonie on September 13, 2018, 08:17:05 AM
That's a nice truck and from what it sounds like to me, you should keep it stock. See the attached image
Title: Re: newb needs direction
Post by: DnSherrill on September 13, 2018, 09:05:18 AM
Thanks, I had it repainted (from navy/gray) in 2006.
What's the argument for leaving it stock? More valuable at resale?
Ultimately I'd like to build a 350 to put in

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Title: Re: newb needs direction
Post by: DnSherrill on September 13, 2018, 05:13:03 PM
I got a new to me aluminum Z28 intake. There's substantial corrosion around the front right coolant port. Should I try building this up with JB Weld and using it? Or return to sender? (https://uploads.tapatalk-cdn.com/20180913/a6b9ab397587a46c756701990a9efb6c.jpg)

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Title: Re: newb needs direction
Post by: Irish_Alley on September 13, 2018, 05:36:49 PM
i wouldnt use JB on that. if anything i would TIG it up. if thats not an option then ship it back
Title: Re: newb needs direction
Post by: DnSherrill on September 13, 2018, 05:38:28 PM
Thanks for the input(https://uploads.tapatalk-cdn.com/20180913/deda8aaf6bbf5bda63701ebb385f1ba3.jpg)

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Title: Re: newb needs direction
Post by: DnSherrill on September 20, 2018, 06:03:34 AM
I'm assuming this 1st picture is the TCC vac sw at the passenger firewall for the 700R4 converter lock up. It can be tied directly to the carb for ported vac?
The second photo is also a vacuum/electrical union, on the passenger side of the distributor. It looks like those wires go into a loom and eventually to the driver's side of trans tail, and the vac hoses came from a TVS. I'm unclear on what this one is. Possible EGR bleed solenoid? Which can be capped off as the EGR is  being deleted.
The third picture is a duplicate of the diagram on my core support.
at the top left of the diagram the label is illegible but should read: 'TIP IN VAC SW'
Thanks in advance . (https://uploads.tapatalk-cdn.com/20180920/32b4864698e837e813da4c29f42aa458.jpg)(https://uploads.tapatalk-cdn.com/20180920/12e4572c85b1f5117392a0add26dd3cd.jpg)(https://uploads.tapatalk-cdn.com/20180920/e599410209515bd98d1e1d77d5dad0b0.jpg)

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Title: Re: newb needs direction
Post by: bd on September 20, 2018, 10:55:27 AM
Pic #1 is the Tip-in Vacuum Switch for ESC.  Pic #2 is the EGR Bleed Solenoid.  The TCC Vacuum Switch should be mounted closer to the brake vacuum booster.
Title: Re: newb needs direction
Post by: DnSherrill on September 20, 2018, 01:54:46 PM
thanks, that makes sense
Title: Re: newb needs direction
Post by: DnSherrill on September 21, 2018, 08:44:31 AM
alright, I see the TCC switch now, it looks like the TIP IN vac sw, but on firewall just above the break booster. I'm still not sure what the large hose pictured above goes to after it passes the firewall down low.  The open end most likely went to the charcoal can in the port closest to the radiator (it snapped off from there during recent removal of ac compressor etc.
At this point here's what I'm thinking for my vac line delete/re-route plan
thanks for suggestions and feedback.
Title: Re: newb needs direction
Post by: DnSherrill on September 23, 2018, 06:35:46 AM
I got everything put back together and no start... Looks like no spark. Maybe my ESC took a dump?
If I bypass it, this is what I should do? Splice green to black, leave the 4 wire plastic connector pulled apart? (https://uploads.tapatalk-cdn.com/20180923/67b062a6acc43aaf7591036ff217ae75.jpg)

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Title: Re: newb needs direction
Post by: DnSherrill on September 24, 2018, 09:41:21 PM
finally got it all put back together, had to adjust the new choke I installed.
Now, the choke light in the speedo gauge stays on, unless I take power away from the choke. I replaced both the oil switch and oil sending unit during this project. Oil pressure gauge reads over 30
Title: Re: newb needs direction
Post by: Henry on September 27, 2018, 03:27:21 PM
Hi Dn:
Concerning the choke light, first thing to check is if it is wired up correctly: you should have a light blue wire going from the choke heater to the oil pressure switch. From this same oil pressure switch connection, you should have a dark blue wire going to the firewall connector. Then, the other terminal on your oil pressure switch should have a pink wire going to the firewall connector. If all this is correct and you have a light that stays on all the time, then there is something not working right with the choke itself as all its current is going through the light instead of the the choke element when the switch allows current to flow to the choke. Maybe the choke element is not grounding properly. Let us know if you are wired up correctly and if you still have the problem. Also, the function of this circuit is more sophisticated than the electrical shematic leads one to believe.
Regards,
Henry
Title: Re: newb needs direction
Post by: DnSherrill on September 27, 2018, 08:28:00 PM
thanks for the input. here is the choke I installed. I  have a gray connector, but it doesn't fit this choke. For now I just clipped the light blue wire on the metal tongue. How is this supposed to be grounded? I don't know if I'll find the correct plastic connector for this.
Title: choke light on
Post by: DnSherrill on September 28, 2018, 08:20:56 AM
here's the wiring currently, appears as you described. later I can check for 12v at the lt blue wire at the choke, i can also check resistances to rule out damaged wiring. not sure what else.
Title: Re: newb needs direction
Post by: bd on September 28, 2018, 09:18:23 AM
Switch the ignition on.  Disconnect the three-wire harness connector from the OPS adjacent to the distributor and disconnect the light blue wire from the choke thermostat.  Does the choke light extinguish?
Title: Re: newb needs direction
Post by: DnSherrill on September 28, 2018, 10:00:44 AM
the dash light goes off when I pull the lt blue wire from the choke tstat. I can check the OPS later. My dash oil pressure gauge reads 30-40
Title: Re: newb needs direction
Post by: bd on September 28, 2018, 10:35:43 AM
Switch the ignition on.  With the lt blu wire connected to the choke t-stat, disconnect the three-wire harness connector from the OPS adjacent to the distributor and jumper the two connector terminals together.  Does the choke light extinguish?
Title: Re: newb needs direction
Post by: bd on September 28, 2018, 11:35:34 AM
Standard Motor Products S-582 (https://www.summitracing.com/parts/smp-s582) for the t-stat pigtail.
Title: Re: newb needs direction
Post by: Henry on September 28, 2018, 01:29:18 PM
Hi Dn:
Electric choke grounding: That riveted plastic choke assembly that mounts to the carb grounds through the carb body either through the rivets or the tang that protrudes into the carb. Sometimes the carb rebuild kits come with a gasket for the other types of chokes and this gasket fits perfectly between the electric choke assy and the carb body...you just need to make sure this gasket is left out. You also need to make sure the tang is properly engaging in the carb when you assemble it. As long as the plastic choke assy has not been opened (rivets removed), these actions should insure you have a good grounding. Did the choke assy come with the carb?...or did you buy it later  and add it to the carb?

Regards,
Henry
Title: Re: newb needs direction
Post by: DnSherrill on September 28, 2018, 03:17:39 PM
this is new choke tstat coil on an M4MED qjet that had a elec choke on it, I damaged the orig choke coil (pulled rivets out) when I was trying to remove the gray plastic pigtail connector.  The tang is engaged, I initially had it wound up to tight and had to take some tension off so the choke valve is slightly open on a cold engine. it starts and idles good now, runs rich....some black smoke at idle, more with accel.  207k miles on the 305, never rebuilt.
Title: Re: newb needs direction
Post by: Henry on September 28, 2018, 06:21:16 PM
Hi Dn:
So from what you said it appears you have the correct choke heater assy for  your M4ME carb. Are you installing/adjusting it per the procedure in either the factory manual or Haynes manual? Do you still have the light that stays on?
Regards,
Henry
Title: Re: newb needs direction
Post by: DnSherrill on September 29, 2018, 09:40:57 PM
Are you installing/adjusting it per the procedure in either the factory manual or Haynes manual? Do you still have the light that stays on?
Regards,
Henry
I installed the new one based on removing the old one (they're identical, except the old one was damaged when I pulled the gray plastic connector off)....initially I had the coil wound up too tight and it ran rich, so I rotated it clockwise and it seems about right now.
As of now the choke light is going off after start up. I recently replaced gauge cluster lights, maybe removing and reinstalling the oil pressure gauge straightened it out?
The LEDs are a nice change. T10 42smd
Title: Re: newb needs direction
Post by: Henry on September 30, 2018, 12:38:08 PM
Hi Dn:
Well, if your choke light goes off after you start the engine and oil pressure comes up all should be well with the choke circuit. I wouldnt be too concerned about the oil pressure gauge reading 30 psi as I dont think they are calibrated to read accurately outside of 60psi. Your voltage gauge should be calibrated pretty close in the 8-14V range and it seems your voltage gauge is reading way too low...if everything is working fine electrically and the truck cranks fine maybe the gauge is bad or not connected correctly.
Regards,
Henry
Title: ESC distributor to 4 pin HEI
Post by: DnSherrill on October 14, 2018, 09:25:01 PM
I removed the ESC  5 pin distributor and put in a new 4 pin HEI vac assist distributor. Still no start and no spark. I measured voltage through the 12 ga solid pink wire that goes to the BAT terminal on the coil. 12.5 v with key in RUN but only 9.5 v with key at START. 0 volt with key out.
thoughts on why?
Title: Re: newb needs direction
Post by: DnSherrill on October 16, 2018, 08:11:13 PM
after using a spark light tester, I'm getting good spark. I had been ignoring the fuel leaking around the air horn gasket and the TB gasket.  Also running very rich and very low MPG. This points to a bad float?
So I can try to replace the float or replace the carb with an eddy 650? which model would I get for my AT?
1986 C10 305 700R4
Title: Re: newb needs direction
Post by: DnSherrill on November 15, 2018, 06:13:54 AM
well, after lots of time spent (learning trial and error) it's clear that my 305 is done. very low compression, head gasket blown. Now to get a replacement. There's a machine shop builder near me that has a 400 0.60 over he'll sell for 1400 and I provide heads.  I found some 350 heads casting number 920 that I feel good about, recently rebuilt asking 300....I'm not feeling too good about the 400 0.60 over
Title: Re: newb needs direction
Post by: 75gmck25 on November 15, 2018, 07:53:06 AM
You are spending too much for a rebuilt engine and old smog heads (sounds like about $1700?).

You could buy a new GM 350 base 250 HP crate engine for about $1700-1800, including a full GM warranty, or move up to a Vortec 350 crate for about $1850 (much better engine overall).   The Vortec will also require a new intake, new flex plate and an electric fuel pump, but all other accessories will move right over.

You need to think about your overall plan before you spend money right away.  Buying an engine with old smog heads, like the 920 or the heads on the base crate engine, will put a hard "cap" on total power potential.  Regardless of what you do in the future, those heads limit what you can get out of a new intake, headers, cam, and other improvements.    Using a more modern head, like the Vortec or any of several low-budget aluminum heads, will give you a much better engine if your goal is something with 350-375 HP, or more.   

Good flowing heads and about 9.5-10.0 compression is where you want to start for a long term build.

Bruce

Bruce
Title: Re: newb needs direction
Post by: DnSherrill on November 15, 2018, 08:40:20 AM
thanks for the input Bruce, also to be considered, my dad lives about 3.5 hours away and has alot of old parts stored, including a 350 short block that may not need to be bored out. That might be the most cost effective. I only want/need an improvement from my 305....250-300 HP will be fine for the foreseen future
Title: Re: newb needs direction
Post by: DnSherrill on January 19, 2019, 08:21:14 PM
update...
the 350 block was bored 0.030 with sealed power new pistons and GM powder rods, using the large valve heads from a 74 (3998920, 1.94/1.5) should end up with about 9.4:1...the cam is a hydraulic flat tappet  Elgin Black Ice ELGICE 200903, identical to GM pn 3863151, lift 0.447/0.447 with 1.5 rocker arms; duration 223/223 @ 0.50....
question:
should I stick with stamped steel 1.5, or should I consider going up to 1.6 roller tip or stamped steel?

Title: Re: newb needs direction
Post by: 75gmck25 on February 07, 2019, 07:27:05 AM
You have plenty of cam duration for your compression, so I don't see any reason to go to 1.6 rockers.  I would just compare rocker prices and decide how deep your pockets are.  Stamped steel will work fine, but rollers will reduce friction and probably reduce heat a little. 

When I installed a new cam and heads I paid a little more to get the Summit store-brand full roller rockers because I was using a new roller cam.  However, stamped steel would have worked fine.

Don't forget that if you go to roller rockers you will need to measure pushrod length (you need the tool), and you might need new pushrods.  Roller rockers will also not fit under stock valve covers, so you need tall covers.    I went through that whole process and it did add a fair amount to the price of my changes.

Bruce