98 Chevy engine stall

ROLLEDS

MEMBER
1998 CHEVROLET TRUCK
V8
2WD
AUTOMATIC

I have a 98 chevy 1500 pickup with 5.7 auto. It starts and runs fine till you open the throttle about half way or more. When you get it to that point it stalls or stumbles and it doesn't matter if it sitting or driving. I picks back up and runs fine when you let off the pedal enough. I have checked everthing I could think of. Also there is no codes showing or pending. Any help will be appreciated. Thanks

Thursday, February 10th, 2011 AT 9:03 PM

3 Replies

JDL

MECHANIC
16,098 POSTS

How long since a tune-up? Use a gage and check fuel pressure. If you have the spider fuel system, it is noted for problems.

Was this

answer

helpful?

Yes

No

Thursday, February 10th, 2011 AT 9:11 PM

ROLLEDS

MEMBER
2 POSTS

I should have stated what I have done. The fuel pressure is fine, I checked that, I installed new plugs cleaned cap and rotor, cleaned and even replaced the mass air meter, and had the ignition module tested and it showed bad so I replaced that. Still same problem. The tp sensor reads right as far as percentage of being open, as well as the ect, and the mass air.

Was this

answer

helpful?

Yes

No

-1

Thursday, February 10th, 2011 AT 9:43 PM

JDL

MECHANIC
16,098 POSTS

Sometimes the fuel poppets need cleaning. The procedure I saw was a shop procedure, don't know if injector cleaner in the gas tank will help or not?

Compare tps sensor signal to map sensor signal at idle. If several volt difference, something wrong.

Was this

answer

helpful?

Yes

No

+1

Thursday, February 10th, 2011 AT 9:58 PM