Loss of power after warm up

[Trusty Rusty]

Hey guys I have a 1998 K2500 with the 5.7l. Here recently it has had acceleration problems after running over 20 minutes. When I say acceleration problems i mean hit the gas and it will get to about 3000 rpm and lose speed. But to throw in a really good twist when this happens I can (while still going down the road) put it in neutral, turn off engine, turn engine back on, and it will run like normal. I dont know where to start. Please help. Thanks, Jon

 

[Swaggerwagon]

Is the CEL (check engine light) on, or has been on recently..?

 

[Trusty Rusty]

it is but the only code thrown is O2 sensor and fuel mixture lean

 

[Swaggerwagon]

thats what i thought...sounds like a dying fuel pump....

 

[Trusty Rusty]

So I guess I will go check fuel pressure. But the good thing is I just replaced it a year ago. so warranty work it is.

 

[shortchevy]

please check your relay first! under the hood in the fuse block. the headlight relay is the same so you can swap them and see if it helps.... before you go do another pump

 

[Trusty Rusty]

Well I have swapped it but havent driven it enough. This weekend I will work on it. Thanks guys will let you know what I find.

 

[shortchevy]

Well I have swapped it but havent driven it enough. This weekend I will work on it. Thanks guys will let you know what I find.

If you end up needing a new relay I have some J-yard ones you can have for free if you pay for shipping

 

[Southern Pride]

Guys my truck does the same thing it will bumble and stumble like it's holding back then it will shoot up in rpm! to where I have the pedal floored at....Is this more related to the CEL being on or the actual code 32- EGR Failure???

Sry no hi jack but related.

 

[shortchevy]

Guys my truck does the same thing it will bumble and stumble like it's holding back then it will shoot up in rpm! to where I have the pedal floored at....Is this more related to the CEL being on or the actual code 32- EGR Failure???

Sry no hi jack but related.

what years your truck? what motor? mine did the same thing as Trusty Rustys when my fuel pump went out... before you do a fuel pump pull the fuel pump ground located right by the pump on the frame off and clean the frame and reattach it. swap your fuel pump relay (with headlight relay) and run some injector cleaner (chevron Techron) if its the same as mine (1997 vortec) you have 8 little tiny injectors in the bottom side of your intake. the holes in the injectors are tiny as well and very easily clogged. Mine started acting up when we switched from winter mix gas to summer mix and im guessing some crap got in there. Just a couple things to try that are cheap. Southern Pride your problem sounds a little different... Is your ERG bad (according to CEL)? your problem sounds like you have a clogged PCV valve or a bad egr