73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: nativetexan on November 05, 2010, 12:47:30 am
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Okay, so I searched for any related topics before I posted so don't hate... ;D
I recently installed a remanufactured 350/tbi all stock motor in my 87 r-10 swb. Now that I am driving it around town again, I have noticed that the tranny seems to be doing some not-so-satisfactory things.
From a stop, if I step on the gas it seems to be a slow take off, 1-2 is okay, then from 2-3 ( i think) [around 45-55mph.] it gets a little weird. It staggers and doesn't go passed 55 until I back my foot off the gas, then I re-apply the pedal and then it shifts.
I have tried this in both drive and overdrive and get the same results. The tranny got rebuilt about two years ago, but I havent put a lot of miles on it because I was taking my time on the motor swap. Should I take it back and explain? Or am I expecting too much from my 700? ??? Because when I drive normaly, it drives good. But, if I want to get on it, it just won't go. (like a tired mule).
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Fluid ok? I'm thinking maybe tv cable, TCC or worn bands. Dunno just a shot in the dark here, but I'd check you fluid level.
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fluid is dead center between the full and low lines. Should I top it off? TV cable is new and adjusted according to specs. Would the bands be worn if it was recently rebuilt? Maybe I should just take it to the shop... I don't think I would be brave enough to try and troubleshoot it anyway...
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I smoked mine on a fresh rebuild (about 50 mi) b/c I didn't dial the tv in. I went from a 250 to a 400.
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I smoked mine on a fresh rebuild (about 50 mi) b/c I didn't dial the tv in. I went from a 250 to a 400.
I adjusted the tv as explained in the haynes book:
1. push button in and push the front part that moves towards the bracket all the way.
2. Stroke the throttle to wide open and hear the adjuster click in to place.
After I didnt get any change, I tried it again,except opened the throttle with the gas pedal inside, thinking that the pedal was off in some way. No change. I have seen other posts (during my searches) that suggest the governor might need to be replaced/rebuilt... Any thoughts about that?
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Any other thoughts?
Thanks
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Sounds like maybe you're not getting enough fuel perhaps? I had a VW TDI that did something similar when the fuel filter was dirty. Wouldn't shift past 4th gear (6 speed auto) and I'd be stuck doing like 60, until I took my foot off the pedal and then it would shift.
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Sticky valve in the valve body? I had this same issue with a 700r4 years ago so used an additive to help free the sticking valve. It worked slightly and may have worked its self out in time but after a teardown and rebuild the problem was gone.
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Update:
So i took my truck to the guy who rebuilt my tranny. We drove it around the block and he showed me that the transmission was shifting, but that the motor was not doing its part. He said it was idling kind of high and I told him I had it timed at 10 degrees behind TBC. He said that was a problem and re-timed it to zero. Picked it up the next day, still the same. I smash the gas and it does downshift, but it doesn't go anywhere. I told him about it and he said that I needed better heads because the power I am looking for is not there. I don't want a lot of hp, I just want it to use what it is suppose to have. I should be able to push down on the gas pedal and speed up. right? Should I take it back to him and have him continue troubleshooting?? I can honestly entertain the idea that it could an engine problem since I was the one who installed the motor. And the fact that it was my first time doing an removal/install. What should I do?? Any advice???
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If he is telling you to swap the heads because your trans is not shifting you should not be letting this guy touch your truck.
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OK this doesn't sound like a transmission issue unless the stator in the converter is bad which we can tell from you doing a stall speed test.
Before you do that let's go back to the engine:
It's a stock TBI 350? When you set the timing to zero did you make sure it was at operating temperature and the EST was in bypass mode? After you verify this clear the codes and drive it. See how it does and scan for any DTC's that return.
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@vile,
Can you refresh my memory of where the EST is on the 87 5.7 setup with the TBI? I don't think they found it. He told me mine doesn't have one. I was there when he was looking for it, so, I know he did try. Anyway, Also, do I just disconnect the battery to clear the codes? I talked to him earlier and told him it was the same... He said to bring it back and he could check compression and the push rod position..
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Wire thats brown with a stripe near the Master Brake booster. A connector is in line in it, and the wire is usually outside the cluster of the rest of the wires.
If you have TBI you have this wire....
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dang! I found it! So, that probably means they didnt do it with it unplugged. Is that a factor. I noticed that it boggs even in park. I give it gas and it goes to about 3 or 4 thousand RPMs and then just boggs out. WTH??
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Warm up engine.
Shut off motor
Unplug wire.
Start motor
Time to 0* TDC.
Shut off motor.
Plug back in
Start motor. If you have a CEL, shut down and remove the ECM fuses and put them back in.
Test drive......
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Ok. One question; what is CEL?
Also, I feel that I should say I did not put my air pump on, nor did I put the coal canister back on... Would either of those things have an affect on my issues?
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Check Engine Light
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@vile,
Can you refresh my memory of where the EST is on the 87 5.7 setup with the TBI? I don't think they found it. He told me mine doesn't have one. I was there when he was looking for it, so, I know he did try. Anyway, Also, do I just disconnect the battery to clear the codes? I talked to him earlier and told him it was the same... He said to bring it back and he could check compression and the push rod position..
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ok, timed it at operating temp, and with the wire unplugged. I disconnect the battery and touched the red to ground. Is that good enough?
If so, then I am still having problems... what next?
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ok, timed it at operating temp, and with the wire unplugged. I disconnect the battery and touched the red to ground. Is that good enough?
If so, then I am still having problems... what next?
You think it might be a fuel issue? The truck sat for about a year with the old gas in the tank...maybe a clogged filter?
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Anyone? Is there anything else I should rule out before taking it in to the shop again?
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OK you cleared the codes but next time disconnect the negative battery cable and wait 30 seconds, don't play with the positive. Explain exactly what it's doing now and check for codes.
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Ok, here is a detailed discreption of the symptoms..
In drive, if I slightly push on the gas, it will accelerate and shift gears just fine. But this is a impractical acceleration rate. If I try to push on the gas to get to a somewhat normal acceleration rate; the engine stops reving, and the truck stops accelerating... well, maybe not totaly, but less than when I am barely pushing on the pedal. This happens at pretty much any amount of me pushing on the pedal. thats about it. I was thinking of recording it on video and posting it. the same thing happens with the tranny in park. If i give it a little gas, its ok. If I push on it any more, it stops reving and bogs out. Kind of like a gargle... and it seems like if I kept doing it, it would stall.
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Does the truck still have the factory catilytic converter on it? My brother in laws truck acted similar and the converter was almost completely pluged but could still drive with light throttle. My 98 camaro did the same thing it was cruising fine the felt like it died but kept running but would bog under any throtle once warm and the converter on it was cloged to the point engine temps rose and the converter got bright red! Wouldn't hurt to check it out if its still got one on it.
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I'd change the fuel filter with each fill up for the next few fill ups.
Also dump the gas if it sat that long and fill with some fresh gas, and add a can of seafoam to the tank.
And if you haven't done it- Fresh plugs gapped correctly, wires cap and rotor.
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Just got the cc changed when I got new exhaust. Cap, rotor and wires were changed within the year.
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Did you check for codes?
check the TPS and check your fuel pressure too.
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vile, I found a thread where you gave instruction on how to get the codes with a obd. But when i get the codes I translate them to numbers? I will check the TPS tomorrow, and try to get the codes. But I will need to know how to convert them.
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ok. figured it out. no codes... is this because i reset them? you guys think it might my advance? do tbis have it?
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You should have gotten at least one code if you did it right.
You checked the TPS? You checked the fuel pressure?
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tps; yes. fuel pressure; no. i think i did it right. i got the number 12 code, but that was it.
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so i replaced the gas cap and fuel filter. it stumbled a little on start up, but i just kept the pedal down and it woke up. ran good for a few miles. then, after i got back in it, it was back at it. i think it is definately fuel relaated because it ran like a champ after the filter change.
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OK this is the last time I ask you this question.... DID YOU CHECK YOUR FUEL PRESSURE?!
:D
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tps; yes. fuel pressure; no. i think i did it right. i got the number 12 code, but that was it.
I haven't. Should I put a guage on it and get actuals or can I just unscrew the filter and see if I have flow?
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For TBI, you need the fuel pressure reading right up to the tbi unit I believe. fuel pressure is a BIG deal with fuel injection.
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Well, I took it in this morning to see if the guys at the shop could figure anything out. The dude wasn't too familiar with BI so I took his theory with a grain of salt. his theory (after watching the injector spraying) was that the injectors are spraying too much when I open up on it and it is causing the carb to flood. Is this a possibility? I am assuming that the computer is responsible for the amount of spray it is giving right? Or is it mechanical? Or is it possible that a sensor is sending a false reading to the computer and it is causing the computer to in turn push more fuel? he suggested that I should just 86 the TBI and get a 4bbl true carb and a mechanical fuel pump... That seems unneccessary.
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In situations like yours I would ask myself "What would VileZambonie do?" and then go check my fuel pressure. 8)
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lol . . . . love it. . . .4 bbl carb and mechanical fuel pump. new distributor too.
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And a new block too, if his isn't cast to accept a mechanical fuel pump.
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Or just a fuel pump...
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In situations like yours I would ask myself "What would VileZambonie do?" and then go check my fuel pressure. 8)
Yes! My thoughts exactly... and I usually do, but, I don't know how to check pressure on a TBI setup? does anybody have any insight on this procedure?
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you need a pressure gauge. Any parts store should be able to get you one. They have a specific one for TBI trucks. It mounts in behind the filter on the tank side. Remove the line from the filter, install the fitting, connect the gauge line and crank the truck. It should be 12-15lbs.
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I don't know much about transmissions, but my friends 87 jeep grand wagoneer had a 360 and 3spd auto. Its kind of sluggish from a stop, and 2nd to 3rd, it either revs up super high and then shifts, like while getting on the freeway, or he has to let of the throttle then give it gas again and it will shift. People say it is the seals in the pump in the tranny leaking so it isn't pushing the gears very strong. Maybe change the tranny filter and replace the pump? I don't know too much about trannys, but that's similar to my friends jeep and that's what he's been told is wrong with it.
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i think its an engine issue. i suspected the tranny at first, but it is shifting. its just not pushing power through the drivetrain...
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I don't know much about transmissions, but my friends 87 jeep grand wagoneer had a 360 and 3spd auto. Its kind of sluggish from a stop, and 2nd to 3rd, it either revs up super high and then shifts, like while getting on the freeway, or he has to let of the throttle then give it gas again and it will shift. People say it is the seals in the pump in the tranny leaking so it isn't pushing the gears very strong. Maybe change the tranny filter and replace the pump? I don't know too much about trannys, but that's similar to my friends jeep and that's what he's been told is wrong with it.
The vacuum hose probably isn't hooked up to the modulator.
Yes check your fuel pressure.
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Vile, about my friends jeep, what is the modulator? Like I said, don't know much about trans.
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Can you find out what trans he has? I don't want to hijack this thread so make a post about it in General Discussion but the vacuum modulator delays upshifts and helps with downshifts in response to engine load. It gets it's signal from a manifold vacuum source.
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Okay vile. Ill find out what trans it is and post it in general. Sorry for post stealing! Ha. Thanks guys. Good luck with your trans/engine issues.
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Got a trouble code 44 today. I havent checked the fuel pressure yet. i am waiting for it to come back to my autozone down the street. I checked the code definition online and it said O2 sensor-too lean. Your thoughts? I will check pressure tomorrow.
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Low fuel pressure/ large vacuum leak
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something strange (i noticed), I double checked my vaccuum lines and I didn't have my EGR solenoid connected. I connected it and it seems to have made it worse.
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Also, it blows my mind that it runs awesome everytime I disconnect the fuel line. I took the back side of the filter off so I could see what it looks like when I turn the pump on. A little bit more than a dribble. >:( But the wierd thing is when I connect it back, it runs like a champ! I wonder why...
But yeah, I am dealing with a low pressure issue. Should I replace the pump or should I do some more checking?
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Bump... please. ;D
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Your EGR solenoid was probably disconnected because it's most likely stuck open making it open the EGR valve = run like poop.
Replace your fuel pump
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Thanks man! Should I replace the solenoid too?? :-\
:o ;D MERRY CHRISTMAS!!! ;D :o
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Not until you test it.
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RIGHT!
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So, I am still having a power loss issue. I know it has something to do with the fuel pressure cuz I put a pressure guage on the line and am losing pressure when I rev it. Dropped the tank, replaced the pump motor, but not the assembly. Still the same no improvement.
Any Ideas?
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the only post i seen is about the tv cable? is there another one or is that it. refresh our memory about your problem. go ahead were listening
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When I rev my pedal, it goes and then it bogs like its not getting fuel. When I drive it does the same thing. If I try to get on it, it just bogs out like it has no power. The last advice I got was that it was the fuel pump, so I replaced the motor not the whole assembly. I have plugged up all the ports on the TBI that I am not using (Smog stuff). I tried running chemtool through it to see if the lines were clogged. The only time I have gotten rid of it was when I took the filter out to replace it thinking the filter was clogged. But it only lasts for the first drive. After I shut it off, it does it again. its a remanufactured 350 that I put in myself with the original TBI on it. I tried not to frankenstein it too much. The only thing I question is the lack of the smog equipment on there with all the vacum ports plugged on the throttle body. And thats pretty much it.
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Did you clean out the bottom of the tank when you replaced the pump?
Have you blown out the fuel lines?
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almost sounds like your old filter was dirty and when you changed it it allowed more dirt and grime to clog the new one
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also get a fuel pressure tester and see what it says
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yup, id surely check that filter again.
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I replaced filters three times, thinking that it was the fix, until I shut the truck off. I put a pressure guage on it, when I rev'd it up and it did what it does, the pressure went down almost close to zero. When I took the filter out I blew out the line going to the engin and the tank from the filter location. I don't know if three filters could have been clogged up. And yes, I cleaned out the tank when I took it down. There wasn't really any junk in there, but did it anyway...
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i had a fuel problem with my truck few years back, before the motor swap. and i thought i had tank cleaned out, i went through 5 fuel filters.
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crank the engine with the fuel line unhooked and have it in a glass jar see what you pick up
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http://www.youtube.com/watch?v=IREmS_b1k5s
Here is a video of what the truck is doing.
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crank the engine with the fuel line unhooked and have it in a glass jar see what you pick up
Uh huh? How do I crank the engine with the fuel line out? I unhooked the filter and turned the ignition to activate the pump and it pumped. It has the right PSI until I put a demand on it via the gas pedal...
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lmao i forgot about the tbi thought it was a carb but key the ignition and see what happens. what’s it look like? any grud
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I did it a while back, didnt see any crud in it.. nice and clean.. :-\
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After you verify your fuel pressure you might rebuild the throttle body. Could be the pressure regulator. Fairly easy job.
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Ok, not to repeat myself ;Dbut, I did check the pressure. It is fine until it gets demand. If you open the throttle on it it will drop to zero until you let off. What would cause a sudden drop in pressure when accelerating ?
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You are being so vague here with the details. What is the pressure? What year is it? Is it stock? You already had a thread on this? Why didn't you pick up there? All I got out of your video was that it's idling way too high and you're running out of fuel or have a plugged exhaust. Any vacuum leaks or kincked fuel lines?
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You are being so vague here with the details. What is the pressure? What year is it? Is it stock? You already had a thread on this? Why didn't you pick up there? All I got out of your video was that it's idling way too high and you're running out of fuel or have a plugged exhaust. Any vacuum leaks or kincked fuel lines?
Sorry guys.
I reposted cuz I couldn't find it and I thought it got closed. But I found it. Here is the link:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=18147.msg150980#msg150980
Its a 87 350 with a stock TBI and intake. I cant remember what the pressure was exactly, but I know it was around 14lbs. but When I stepped on the gas to simulate the issue, it dropped down to <5lbs. And sometimes under 1lb. The idle might be high in the video because I didn't let it warm up. IDK. I took the filter out after installing the new motor and blew out the supply line from where the filter was. But not the other lines. What are the other two lines for by the way?
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Any takers? Vile, Your thoughts are always appreciated sir.
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one is a vent the other is return. would it be possible to check the signal to the pump while its doing the pressure drop. to see if the pump is getting a signal to stop pumping or its on the pump side thats causing the problem
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Is there something that will do that? I thought it was just a constant 12v to the pump when the ignition is on...I will see if I can check volt while it is dropping. Thanks
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OK Captain obvious here but you do have ample fuel in the tank right?
After that, inspect for kinked/collapsed hoses. Is it dual tank?
The idle is too high even if it's cold. Check for vacuum leaks.
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OK Captain obvious here but you do have ample fuel in the tank right?
After that, inspect for kinked/collapsed hoses. Is it dual tank?
The idle is too high even if it's cold. Check for vacuum leaks.
I'll check hoses, its a single tank. And I will revisit the vacuum leak theory. Is there a way to visualy see vacuum leaks? Soapy water?
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So, I bought a set of caps for the open ports... I think that was the culprit. It is running a lot better. One thing I notice is that when I do a quick acceleration, it stays at 45mph until I let off the pedal and then it will speed up. Any ideas about that issue? I think it might be the OD on the 700R4 that I had rebuilt.
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Well I swear, as soon as I say its fixed it slaps me in the face. Started it up today and its doing it again. Back to the drawing board... ???
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did it get any better or still the same old problems as before?
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Nope. Not really. I started it up and rev'd it a few times. Same dang thing as before.
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No kinked hoses. any other ideas. I think I might take it in and let the pros take care of it. I just dont know what it is. What can cause a significant fuel pressure drop while gauged behind the fuel filter??? :'( :'( :'(
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I think you should take the advice that was suggested earlier and replace the fuel pressure regulator. It sounds to me as if the spring in it is broken/weak and is unable to regulate the pressure when the vacuum decreases. It should maintain 13-15 psi regardless of throttle position or engine load. Have you put a vacuum guage on it while revving it and idling? Checked for collapsed or plugged exhaust? There are so many possibilities for why it is lacking power..If you're willing to do the leg work we can get to the bottom of it.
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Checked the timing just now. Its good. I even revd it while adjusting the timing to different setpoints. Do you think it could be the regulator if the guage was behind the fuel filter? Thats probably a dumb question.
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Pinch the return line hose and find out.
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Ok so I took a hint and removed the injector assembly from the TBI. I am going to replace the regulator but, The fuel pressure regulator housing is questionable as well. Check out the pics below. The inlet looks weird. Is that what it should look like? Also, the little lever on the side is not moving. Is it suppose to?
(http://img171.imageshack.us/img171/782/dscn0225q.jpg) (http://imageshack.us/photo/my-images/171/dscn0225q.jpg/)
(http://img8.imageshack.us/img8/8641/dscn0224800x600.jpg)
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There isn't an inlet on the regulator, that is the sealed off plug for the pressure setting, the arm in where it was adjusted to, it doesn't move, there is a spring behind it.
I could have swore I posted my TBI rebuild thread here but apparently not... I will add that to the list. But if you drill out that end and then slot it you can make the pressure adjustable.
Anyway, what did the gasket look like that came off?
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The gasket was real brittle. It broke in the middle when i took it off. The regulator comes with a new gasket. So i will replace the regulator and see what happens. A tbi rebuild thread would be awesooome!
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Replaced the regulator. No dice. No improvement. Where can i get a vaccuum gauge?
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You can get a Vacuum gauge at any auto parts store.
If it makes you feel any better, my R10 JUST started doing this.... Yippie!
When you replaced the regulator you got a new diaphragm and gasket with it right.
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it was a rebuild kit. It came with the diaphram, a spring (which was longer than the one that was in there so I kept the original), all gaskets, and two rods, that I have no idea where they go. But yeah the new diaphram and gaskets are in there. I guess I will go look for a vacuum gauge tomorrow. ???
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Maybe you should use the longer one?.... Maybe thats yoyr problem is the spring in the reg squished?
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I was thinking the same thing...
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Put the new Spring in there... The rods are for aligning everything up with the spring in there.
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Update: new spring is the short one. Swapped it in and still the same. About the rods, Do they go in the holes next to the screw holes? Do they stay in there? They werent in therr when i took it off. I notice that it happens when the throttle is about a quarter or a third open. You think the injectors are faulty and flooding the intake?
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Here is a direct link of a video i took of the injector during the acceleration.
http://img803.imageshack.us/img803/4975/ayh.mp4 (http://img803.imageshack.us/img803/4975/ayh.mp4)
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Anybody think it might be the HEI? A friend at work said he had the same issues with a jeep he had...
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While I wouldn't rule out a problem with the HEI, lets focus on one issue at a time.
Have you tried pinching the return line? Do this only for testing! This should raise the pressure. If it doesn't you have a problem with the supply; weak pump/ wrong pump, hose connecting the pump to the main assy is split (just saw this scenario recently), plugged filter, kinked or plugged pressure line.
In addition to pressure have you checked the volume? Does anyone have the specs? I'm unsure where my manual is.
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My bad, My setup is not HEI, it has ignition coil sitting next to the distributor. Anyway, I havent tried the pinched line test. I need to go get the pressure gauges from the zone and then I will check that out. Thanks. When I replaced the pump motor, I cut the end off the hose because it was ugly. Its all good in there now. my lines aren't pinched, I followed it all the way to the tbi. Also, here recently I have noticed a slight whistling sound while idling... ???
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Th hat slight whistling sound could be 1 of 2 things, it could be just your tbi throat whistling or a vacuum leak. Put your hand over the mouth of the throttle body while its idling and see if the whistling sound changes. If it doesnt, grab a can of wd40 and spray it on all of your vacuum lines, around the base of your tbi, and around where your intake bolts to the heads. If the idle raises at all when you spray a certain area, then you have a vacuum leak
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The truck will definitley be HEI, but computer controlled.
The rods on the diaphram are for alignment only...
I would pinch off the return line and see if it makes a difference. Just use some vice grips and slightly clamp on the return line.
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Whoa! Wait a minute captain, are you saying that if my setup is not HEI, then its not right??is HEI defined by the coil being set on top of the distributor cap instead of mounted to the intake like mine? I thought maybe it was an option but if you are telling me that its only HEI for the 87 5.7 350ci w tbi setup, then i guess some tool did a lil junkyard jerry rig with a ignition coil and a regular distributor. Do you think this could be causing some of my problems?? Should I go back to hei? Thank you for the precious info guys!
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Quick thouth though. If it is suppose to be hei, then why do i have the plugs for the ignition module and the wire for the esc?
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you got the right thing.. its electronic. HEI = High Energy Ignition, there is the early model with the big cap and the late model with the seperate coil mounted to the intake on the TBI trucks.
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8) cooool 8)
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So I forgot to mention that i put a trashbag over the aircleaner on my truck and it didnt die or change idle speed or anything. Is that a pretty good way to confirm that it has a vacuum leak issue? My friend came over and hooked up his scanner to it. No codes. Nothing out of the ordinary. He still thinks it might be the cc. I will check for vacuum leaks and test to see if the cc failed by removing the o2 sensors to provide a place for the exhaust to exit. Lemme know what yall think.
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well im going to go out on a limb and say vacuum leak, for one back in Dec i think you said you had a code 44 low fuel or vacuum leak. and the whistle is a sign of vacuum leak, and the trash bag test is a sign of vacuum leak. now i think the tbi base plate gaskets are notorious for going bad. Use a hand torch without it being lit and turn it on and follow the mounting surfaces where a gasket should be it should rev up
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well im going to go out on a limb and say vacuum leak, for one back in Dec i think you said you had a code 44 low fuel or vacuum leak. and the whistle is a sign of vacuum leak, and the trash bag test is a sign of vacuum leak. now i think the tbi base plate gaskets are notorious for going bad. Use a hand torch without it being lit and turn it on and follow the mounting surfaces where a gasket should be it should rev up
What if I used carb cleaner or something like that? Would it rev up? Also, the gasket is new but maybe the TBI is warped. Does that happen? I say that because I had this issue before I put the remanufactured engine in there.
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might be the tb then. idk about the carb cleaner. this is what im thinking. something can be water tight but not air tight due to water molecules being bigger than air molecules. so if you spray a liquid then it might not find the leak if you were to spray air then it should find a finer leak
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Irish, if the leak was so small that water cant get in, I dont think it would make a difference. But, carb cleaner or WD40 would still work because even if the fluid cant get in, the fumes will.
Native, can you recap what your issue is for me? Slow acceleration? Does it bog down with throttlw? Does it back fire through the exhaust or through the carb? Have you checked your initial timing? Have you tried advancing or retarding your timing to see if changes? What do your spark.plugs look like? spray some form of accelerant(WD40, carb cleaner. NOT brake cleaner) on all of your vacuum.lines, all of the vacuum connections, your brake booster, where your intake bolts to the heads, the base of your throttle body, the sides of your throttle body. Spray some directly into the mouth of the tbi and listen to the rpms raise, then youll know what to look/listen for.
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Ok when there is no serious demand on the engine it runs good. If demand is put on it, the engine bogs out like its going to die until the throttle is backed off. This happens while driving and while idling. I watched the injectors spray gas so i know it is getting fuel. But the gas pressure drops while the demand was put on. I have played with the timing and it seems to do it at any point. I checked it at zero, -10, and +10. I am going to retime once again to zero and check the stuff you guys suggested. Also, when i put a vacuum gauge on it. What am i looking for? Where should i connect it?
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Plug the vacuum gauge into a manifold vacuum port. One that had vacuum at idle. I dont know what to tell you on what to look for. Can you tell me what your spark plug electrodes look like? I installed a new intake on my buddies truck and somehow while doing so, one of the air/fuel mixture screws came almost all the way out. It ran like crap and tried to stall when you let off the throttle and came to a stop.
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When doing the timing you have the vacuum plug off and the idle below 800 rpm. What does the timing go to when you run the engine at 3000 rpm?
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Not sure about the RPMs. But I just got done retiming the motor to 0 with the EST unplugged. When I plugged it back in and rechecked the timing, it was way off the scale. Im guessing over 10 degrees ahead of 0. If you are looking at it from the front of the truck, it would be about 10-14 degrees to the left of 0. What is that about??? And when I revd it, it took off even further to the left. Also, when I first started timing it, it started hopping around a bunch. From 0 to the right of 0 about 5 degrees. just back n forth. A few seconds in one spot then a few seconds in another spot. What does that mean? Bad ECM?
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When you hooked up the vacuum line back onto the distributor it called for the vacuum advance to kick in. Reving the motor is calling for the mechanical advance to ramp up. Both normal thing but you need a dail back timing light a tach to determine if the values are correct.
With timing jumping around you may have weak springs or worn out weight.
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Well i dont have the vacuum line on my distributor. Just the est. Also, the motor is remanufactured so it should be in pretty good shape.
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Do you have headers or manifolds? What do your spark plugs look like? Can you take a pic of them
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did you ever check for a leak
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I will check plugs and take pictures. And check for leaks. Thanks guys
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Okay, bought some starting fluid to test for leaks and a vacuum gauge. Put the vacuum gauge inline with the EGR vacuum solenoid. It idled at about 22. and then when I increased throttle a little, it would drop to about 15. If I revd it to the place where it bogs out, it dropped to 5. I switched the gauge to the port on the tbi below the breather on the right, I think it is A. gauge stayed at 0 until I increased throttle and then it would shoot to about 10-15.
As for the spray test with the starting fluid... it didnt do anything when I sprayed it on the manifold and brake booster and line. Any thoughts. Can someone define what the readings I got?
UPDATE___________________________________
(http://img7.imageshack.us/img7/8742/securedownloadcii.jpg) (http://imageshack.us/photo/my-images/7/securedownloadcii.jpg/)
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Here are my plugs... Yikes. I got problems.
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Air fuel mixture. Too rich on one bank, too lean on the other.
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Air fuel mixture. Too rich on one bank, too lean on the other.
what now? How do I resolve that?
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Air fuel mixture. Too rich on one bank, too lean on the other.
You looking at the same pic I am? 3 black plugs on one side and 2 on the other? Who rebuilt this motor? Did you go through a break in process?
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lol i was thinking the same thing. have you done a pressure check?
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3 black plugs on one side and 2 on the other? Who rebuilt this motor? Did you go through a break in process?
X2
If I had this problem for this long my next steps would be looking into why all 8 plugs were not burning the same. Too me it sounds like there are multiple things wrong with this.
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is that the order they came out in? top side being 1357 bottom being 2468? if so the ones that are lean are alternating firing order i.e. 1,4,6 dont know what that means but it seems odd
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2, 3, 5, 8 are on one half of the intake and 1, 4, 6, 7 are on the other half. I didnt thi nj k when I said bank, I meant plane.
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2, 3, 5, 8 are on one half of the intake and 1, 4, 6, 7 are on the other half. I didnt thi nj k when I said bank, I meant plane.
que? where did you get that info from? we knew what you meant by bank
you bought your repair manual from ebay didnt you?
i learned my lesson from them before
uıɐƃɐ ʎɐqǝ ɯoɹɟ pɹɐoqʎǝʞ ɐ ƃuıʎnq ɹǝʌǝu ɯɐ ı
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Follow the intake runners to the base, youll see what I mean. The stock intake is dual plane.
In this pic, runners 2, 3, 5, 8 are on the raised plane on bottom and 1, 4, 6, 7 are on the lower plane on the top.
(http://www.elmersauto.com/jun2010storeint29.jpg)
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Yes the plugs are in the order they came out. Left side is driver. A friend is gonna come help me do a leak down test. Im too much of a newb to know what would cause a rich/lean issue so if someone could break it down for i would apreciate it.
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never really look at it that way 79 lol
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Bank to bank (left vs right) is how you determine the cylinder numbers universally...
Driver side of the motor is ODD numbered 1,3,5,7
Passenger side is Even numbered 2,4,6,8
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So any ideas on my vacuum gauge readings?
http://imageshack.us/clip/my-videos/535/r7d.mp4/
(http://imageshack.us/clip/my-videos/535/r7d.mp4/)
Here is a video of it.
Idle seems good. When I barely push on the throttle, the engine starts to shake and then as I increase throttle it goes away. When I hit the throttle real hard, it sounds like it is backfiring in the tbi or manifold. When I increase throttle gradualy up to wherei it starts to bog, it seems like it backfires out the muffler when I let go of the throttle.
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So any ideas on my vacuum gauge readings?
http://imageshack.us/clip/my-videos/535/r7d.mp4/
(http://imageshack.us/clip/my-videos/535/r7d.mp4/)
Here is a video of it.
Idle seems good. When I barely push on the throttle, the engine starts to shake and then as I increase throttle it goes away. When I hit the throttle real hard, it sounds like it is backfiring in the tbi or manifold. When I increase throttle gradualy up to wherei it starts to bog, it seems like it backfires out the muffler when I let go of the throttle.
Anyone?
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Vaccum guage looks pretty normal. :)
That tells us that the rings and valves are sealing. Also I think we can rule out a plugged exhaust.
I would check the Throttle position sensor and also the M.A.P. sensor for a bad spot with a analog meter.
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I do question the MAP. I tested the TPS and it ohm'd to specs with a meter.
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i wsa working on a geo oncecant remember what it was doing but i unplugged the map problem didnt change swapped it with one of another truck fixed the problem
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Well, I did unplug it and it did get worse, but I will try to find another one. It might just be failing in that particular range huh?
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only had it fail 100% not in a particular range
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Native, just wondering if you found your problem? I have the exact same thing going on in my 89 V3500 with 454tbi, I have replaced all kinds of parts and still nothing. I am starting to wonder about the TPS but wondered if you come up with anything.