Engine stumbles like it is starving for fuel or air?

B. PLAIR

MEMBER
1997 CHEVROLET TAHOE
5.7L
V8
4WD
AUTOMATIC
268,000 MILES

My truck runs great until after about ten miles of driving then all of a sudden it can't get out of its own way. I can shut it off and immediately start it back up then it runs like it should but only for a limited amount of time. I've replaced and upgraded the fuel injection, new GM pump, fuel filter, coolant temperature sensor, mass air flow sensor, new plugs and wires, cleaned the throttle body and replaced the gaskets on both the throttle body and upper intake. I'm completely lost, please help.

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

Are there any codes? I would run them even if the check engine light is not on. Here is a guide to help. You can get a code scanner from Amazon for about $20.00.

Here is a guide/video to show you how:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is a scanner link:

https://amzn.to/3Qi1SS6

You could have a PCM going out which will cause this problem and is common with that many miles, and when this part goes out it will not have a trouble code FYI.

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Friday, August 5th, 2022 AT 5:11 PM

B. PLAIR

MEMBER
2 POSTS

The only code I'm getting now is a misfire on #6 but that only pops up after the truck starts running funny. Thanks for the link but I already have a scanner. When I look at live data, the MAF reading is always in the red along with the TPS when I accelerate. How do I confirm that it is or isn't the PCM?

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Friday, August 5th, 2022 AT 11:18 PM

KEN L