Starts but shuts off unless throttling high RPM's

JOHNSONAPE

MEMBER
1998 CHEVROLET S-10
2.2L
4 CYL
2WD
MANUAL
180,000 MILES

Drove 2 miles yesterday and suddenly started bucking, slowed down to take a corner and truck shut off. Started right up but shut off every time I let off the gas. Limped it back home driving 45 in third gear. Has been running like a champ before this for the last year. Will stay running in neutral with no miss at high rpm. Any help appreciated.

Thursday, April 9th, 2020 AT 10:28 AM

5 Replies

KASEKENNY

MECHANIC
18,907 POSTS

Can you give a little more detail about when this stalls? I understand that the engine will keep running if you give it throttle but you said it runs well in neutral but does this mean it will run without throttle input or no matter what you have to give it throttle to run?

If this will stall at idle no matter what, it sounds like the IAC. Review this material and let me know what you find.

Here is a guide that covers the basic things that cause stall at idle:

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

Let me know what you find with this and we can go from there. Thanks

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Thursday, April 9th, 2020 AT 10:57 AM

JOHNSONAPE

MEMBER
22 POSTS

Thanks for your input. Yes, I have to throttle it no matter what. I will order a IAC online as I'm not going to pay $75.00 for it when I can get it for $20.00. I did pull it out and upon inspection it is pretty badly coked. Reading some of your other articles I did clean the ground for the fuel pump and snotted out the throttle body. I also bought a fuel filter to install. I was looking for the EGR valve but couldn't locate it. I know they can cause issues as well. I'm not sure how soon I will get the IAC but will update. Thanks for your help.

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Thursday, April 9th, 2020 AT 2:03 PM

KASEKENNY

MECHANIC
18,907 POSTS

Sounds great. If the IAC was coked up then clearly that should be the first thing as you are doing. The EGR will most likely not cause a stall like this but we can address that if the IAC does not fix it but I attached the location.

Keep us updated with what you find. Thanks

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Thursday, April 9th, 2020 AT 2:30 PM

JOHNSONAPE

MEMBER
22 POSTS

Okay, so I found a IAC online for $11.00 and ordered it but in the meantime I pulled the old one and snotted it out with throttle body cleaner and installed my gas filter. Upon inspection of the gas filter I shook it and heard something inside and dumped it out backwards and a lot of small black debris came out. I also noticed some bubbles laying on top of the gas and bought some Heet to take care of condensation in my fuel. I'm not sure what fixed it but now my truck is running like it did before. My IAC will be here sometime next week but I may just hold on to it until I run into this problem again. What do you think? Thanks for your help in this matter KASEKENNY1.

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Sunday, April 12th, 2020 AT 4:38 PM

DANNY L

MECHANIC
5,648 POSTS

Hello, I'm Danny.

Just adding my 2 cents. Sounds like you just had a plugged fuel filter with contamination. Before you install the IAC I would just suggest verifying correct fuel pressure now. If you don't have a fuel pressure tester most local auto parts stores have a tool loaner program and can rent you one.Here is a tutorial showing what is involved:

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

The specifications for your truck is with Key On/Engine Off 41-47 p.s.i
Hope this helps and thanks again for using 2CarPros.

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Sunday, April 12th, 2020 AT 7:48 PM