1991 Chevy S-10 WILL NOT STAY RUNNING

Tiny
CANTER6
  • MEMBER
  • 1991 CHEVROLET S-10
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 197,000 MILES
I just bought a 91 s10 4.3l tbi, last week that had been sitting for a few months. Yesterday coming back from my lunch break I was pulling into the parking lot when the engine died. On re-start, it would turn over and run for a second, then quit. Now if I feather the throttle it will stay running (really bad and even backfire through the "carb", almost like it is out of time) the faster I feather it the smoother it will run, which leads me away from timing issue and into fueling, when I turn the key I can hear the fuel system pressurizing, and I just got back from an 1100 mile trip this weekend with no problems, so condensation in the tank isnt looking to be an issue, I check the dist. Cap and it isnt loose. I have not tested the fuel pressure as of yet, which I plan on doing hopefully today if the storms clear up. Ive read up a bit before posting this, that possible reasons could be the egr valve being stuck open, and/or the ecm being toast. Problem is I haven been able to locate the ecm to visibly inspect the card, (only had the truck now for about 3 days. And two of them have been on the road driving it.

EDIT******************************
last night fed her starting fluid through the throttle bodie, and she started up and ran good (as long as starting fluid keeps being squirted), BUT the injectors ARE pulsing and you can visibly see them squirting. Now im at a loss, going to pull off the injector assembly today/tonght. And see if garbage has collected in the bottom of them. Oh yeah the cap/rotor/ and ign. Ctl mod are new as well.

UPDATE*********************************
jumped a and b under the dash and the only code that came up was 24 IIRC which according to the guide I found online is a VSS code. Doesnt seem like it would be a reason for the no-start, but figured I would hrow that in as well.
Tuesday, April 14th, 2009 AT 8:36 AM

9 Replies

Tiny
RACEFAN966
  • MECHANIC
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First let me say don't use starting fluid it is not good on a engine at all if you must do something like that use carb cleaner it is less harmful. Now with that said when was the last time you changed the fuel filter? Have you done a fuel pressure test? Get back to me and we will go from there.
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
CANTER6
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I havent changed anything on it other than cap/ rotor button, and ignition module, since I purchased the truck. I went out last night to look for a port to check fuel pressure. And was unable to locate it (traced fuel line from body of tbi all the way down to where I could not see it anymore below the engine.
I plan on replacing the fuel filter this weekend (saturday) as I am unableto get out there unitll after work, and have daylight constraints, in the parking lot it is in.

Where would the check port be located at?
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
RACEFAN966
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I would first change the fuel filter so you can rule that out. As for a port to check pressure there isn't on on this model. They sell a 40 dollar adapter that you put in place of the fuel filter just for testing. It should be about 15 psi. Let me know how it goes.
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
CANTER6
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Just changed the fuel filter out in the parking lot (lunch break) the filter that came off, was reletively new looking, and had VERY little debris in it on the input side and next to none on the output side, tried turning the truck over and still nothing, I will see if I can locate a pressure tester from one of the guys in the shop out back and get back to you,
one quick question, when turning the key to the run position (not start) you can hear the fuel pump relay engage and the pump whine to pressurize the system, then a click again, is this normal?
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
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Okay got a pressure tester, from one of the guys out back, gonna see if I can get one of those adapters you told me about,

i have the upper part of the tbi removed at this time to go ahead and rebuild it it with new gaskets etc.
And when I pulled it off it was pretty filthy, I disassembled it and cleaned it in the parts washer.
While it was off I turned the key to the run position (fuel lines disconnected from the tbi housing) and got alittle gurgle and a brief spurt of fuel,

its looking more like the fuel pump now, as I was easily able to hold my thumb over the line, and not spray fuel. Going to check pressure anyways just to be sure.
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
RACEFAN966
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Yea sounds like the fuel pump is going to need to be replaced. You will have to drop the tank to do this too. Let me know if you need anything.
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
CANTER6
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Dropped the tank today (if I ever have to replace the pump again im cutting a hole in the bed ha ha ha) seriously though the truck really is in bad shape (was in a crash and now has body panels from 88-91 on it, taste the rainbow! Lol

anyhow, turns out the pump was good it was the hose between the pump and the rest of the fuel pump assembly had split, changed the pump along with it, and sock, and keeping the old pump in case I ever need it to siphon somthing or what not.
Thanks for slowing me down, and focusing my efforts more carefully!
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
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Tried leaving you some positive feedback as well, but it seems I have none to give :/ just know I appreciate you!
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Tuesday, August 21st, 2018 AT 3:26 PM
Tiny
RACEFAN966
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Hey no problem thats why I do this. I also volunteer my time to the needy for there car problems too. I guess it is just my calling and I like working on cars too. Thanks for you comment and if there is anything else you need just ask. You have a great day and God Bless.
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Tuesday, August 21st, 2018 AT 3:26 PM

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