Engine stalls when at idle?

Tiny
KEVIN GREEN2
  • MEMBER
  • 1998 CHEVROLET S-10
  • 4.3L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 135,000 MILES
I just replaced the intake manifold gasket, water pump, crankshaft positioning sensor, spark plugs and wires, and wiring harness. Truck is very hard to start and once it is started it will idle just fine in neutral. Once you put it into either reverse or drive it stalls out. Any suggestions as to what it might be?
Sunday, November 17th, 2019 AT 2:22 AM

51 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning,

If you 2 foot it, will it stay running?

https://www.2carpros.com/articles/stall-at-idle

Roy
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Sunday, November 17th, 2019 AT 5:58 AM
Tiny
KEVIN GREEN2
  • MEMBER
  • 8 POSTS
Yes, if you 2 foot it while driving it will stay running. But that depends on if we can get it to start. And it idles just fine and stays running while in neutral.
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Sunday, November 17th, 2019 AT 6:20 AM
Tiny
ASEMASTER6371
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Okay, was this the issue prior to your repairs?

Did you check for vacuum leaks?

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Did you check the fuel pressure?

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I am wondering to about the distributor. Did you verify the cam retard with the engine running?

Roy
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Sunday, November 17th, 2019 AT 6:26 AM
Tiny
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No this was not an issue prior to the repairs. And yes we did a vacuum check after reinstalling the intake manifold. Haven't done a fuel pressure check yet. And did not verify cam retard. What is the cam retard?
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Sunday, November 17th, 2019 AT 6:53 AM
Tiny
ASEMASTER6371
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The distributor is actually a cam sensor. Timing is set through the ECM. The cam retard is alignment of the crank sensor to the cam sensor. They have to aligned with 2 degrees of each other.

Are there any codes set?

Roy
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Sunday, November 17th, 2019 AT 7:03 AM
Tiny
KEVIN GREEN2
  • MEMBER
  • 8 POSTS
Don't have a code reader and can't get it to start and run long enough to take it somewhere.
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Sunday, November 17th, 2019 AT 7:07 AM
Tiny
ASEMASTER6371
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Start with checking the fuel pressure.

Let us make sure it is not fuel delivery related.

Roy
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Sunday, November 17th, 2019 AT 7:15 AM
Tiny
KEVIN GREEN2
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Okay.
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Sunday, November 17th, 2019 AT 7:16 AM
Tiny
ASEMASTER6371
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Keep me updated.

Roy
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Sunday, November 17th, 2019 AT 7:28 AM
Tiny
KEVIN GREEN2
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Okay. So I got the truck started. I didn't do a fuel pressure check yet. But when it's idling in neutral the rpm's are around 500. And when I held the brake and put it into drive I had the gas pedal all the way to the floor and the rpm's were only around 2000.
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Sunday, November 17th, 2019 AT 8:54 PM
Tiny
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Is the check engine light on?

Roy
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Monday, November 18th, 2019 AT 2:31 AM
Tiny
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Yes.
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Monday, November 18th, 2019 AT 5:03 AM
Tiny
ASEMASTER6371
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Okay, it sounds like you have the distributor in incorrect.

I attached the procedure for installing it.

Roy

IMPORTANT: The engine front cover has 2 alignment tabs and the crankshaft balancer has 2 alignment marks (spaced 90 degrees apart) which are used for positioning number 1 piston at top dead center (TDC). With the piston on the compression stroke and at top dead center, the crankshaft balancer alignment mark (1) must align with the engine front cover tab (2) and the crankshaft balancer alignment mark (4) must align with the engine front cover tab (3).

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1. Rotate the crankshaft balancer clockwise until the alignment marks on the crankshaft balancer are aligned with the tabs on the engine front cover and the number 1 piston is at top dead center of the compression stroke.

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2. Remove the distributor cap bolts and discard.
3. Remove the distributor cap.

Image

4. Install a NEW distributor gasket onto the distributor.
5. Align the indent hole on the driven gear with the paint mark on the distributor housing.

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6. Ensure that the distributor rotor segment points to the cap hold area.
7. Align the slotted tang in the oil pump driveshaft with the distributor driveshaft.
Rotate the oil pump driveshaft with a screwdriver if necessary.

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8. Install the distributor and distributor clamp.
The flat in the distributor housing must point toward the front of the engine.

ImageOpen In New TabZoom/Print

9. Once the distributor is fully seated, align the distributor rotor segment with the number 6 pointer (1) that is cast into the distributor base.
If the distributor rotor segment does not come within a few degrees of the number 6 pointer (1), the gear mesh between the distributor and camshaft may be off a tooth or more. Repeat the procedure again in order to achieve proper alignment.

ImageOpen In New TabZoom/Print

10. Install the distributor clamp bolt.
Tighten the distributor clamp bolt to 25 Nm (18 ft. Lbs.).
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Monday, November 18th, 2019 AT 5:31 AM
Tiny
KEVIN GREEN2
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Okay, I will give that a try and let you know what happens. Thank you
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Monday, November 18th, 2019 AT 6:03 AM
Tiny
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You are welcome.

Keep us updated.

Roy
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Monday, November 18th, 2019 AT 6:09 AM
Tiny
MIKE SHELTON
  • MEMBER
  • 1 POST
  • 1997 CHEVROLET S-10
  • 2.2L
  • 4 CYL
  • MANUAL
  • 15,000 MILES
Will idle when cold but will not when hot and you can smell gas form exhaust.
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Friday, January 29th, 2021 AT 11:00 AM (Merged)
Tiny
HMAC300
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Check fuel pressure with a gauge first auto parts rent gauge should be 41-47 psi key on only. if that is okay scan for codes. see link.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator
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Friday, January 29th, 2021 AT 11:00 AM (Merged)
Tiny
ROBERK26
  • MEMBER
  • 5 POSTS
  • 1994 CHEVROLET S-10
  • 4.3L
  • V6
  • 4WD
  • AUTOMATIC
  • 108,000 MILES
Blazer with 4.3l Vortec. I have a recurring intermittent issue where my truck will stall out when I put it in gear--park to reverse, park to drive, reverse-neutral-drive, etc. Pretty much only happens in parking lots within a minute of starting the engine.

This doesn't happen every time, and has happened with a warm and cold engine, and in moderate and ridiculously cold ambient temperatures. (Range from +45 to -25 f, haven't owned the truck during warmer months yet).

I just recently replaced the fuel pump/screen and fuel filter. I also replaced the spark plugs just because the plugs that were in there looked pretty old.

This is not an emergency or anything, I can keep the truck from stalling by giving it a little gas as I put it in gear. I am just wondering what could be causing this issue, and how to fix it.
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Friday, January 29th, 2021 AT 11:01 AM (Merged)
Tiny
ASEMASTER6371
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Good evening,

Are there any codes set in the system?

I would start by cleaning the throttle body of all carbon.

https://www.2carpros.com/articles/stall-at-idle

https://www.2carpros.com/articles/throttle-actuator-service

This could also be an idle air control motor. I attached a picture and procedure.

Roy
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Friday, January 29th, 2021 AT 11:01 AM (Merged)
Tiny
JAGFIX
  • MEMBER
  • 11 POSTS
  • 1994 CHEVROLET S-10
  • 79,000 MILES
It is a 1994 S-10 TBI 4.3L.4x4. The engine will start and idle a couple seconds then immediately stalls. It will start right back up and idle for a few more seconds and stall again. After numerous attempts, it will start and stay running without stalling and I can drive on like normal with no problems and it might be normal for a few days then start acting up again. I replaced the ignition module but that didn't fix it. I tried spraying starting fluid into the throttle body just as it was about to stall and it appears to stay running until I stop spraying indicating a fueling issue. I swapped out the fuel pump relay and that didn't help either. Walking to and from work in the cold weather is starting to suck. Any help will be greatly appreciated as I am at a loss.
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Friday, January 29th, 2021 AT 11:01 AM (Merged)

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