What happened?

[THISISWEIRD]

So I'm riding down a really rough road today and all of a sudden, my truck starts running really, really rough....like its about to cut off. RPMs are making big swings up and down (about 500 up and 500 down). If I floor it, it acts okay until I let off a bit. Finally, at the stop sign (when I have to let off) it dies.

I call a friend with a tow truck and try to start it while I wait. I can hear the pump prime but she still won't start. Occasionally, she makes about a 1-2 second run and then dies. After about 20-30 minutes, she starts right up and now runs fine.

It's great that she's running fine, but I need to know what happened so I can prevent it in the future.

It's a 91' K5...stock in the engine area. About 2 months ago, I replaced the fuel pump after she left me stranded a few times, but as I mentioned, I could hear the pump prime each time I tried to start it. I'm guessing it's not the pump, but I don't know. It's like something got knocked loose but I don't know how it would start back up like it did. Maybe something with the TPS?

Any help is appreciated.

 

[blazin_blazer]

maybe water in gas?

 

[THISISWEIRD]

That thought did cross my mind. I did get some gas just before that.

 

[driney]

You might be on th right track with the TPS. I had one go bad, would run fine with the accelerator on the floor, but wouldn't run at a steady speed. After it cooled off it would run fine for a while.

 

[THISISWEIRD]

Any other ideas?

 

[longbedder]

I'm guessing either ignition system or fuel system...really tough to say which.

I'd get an ALDL cable and free software, then check for codes. If there's no codes, try driving on that same road and see if you can repeat the problem while loggin data.

With TBI and no data you could throw alot of time and parts at it without addressing the problem.

 

[Tabb]

Sounds like it might be the ignition control module, once the engine gets hot the module starts cutting out. Once its cools off it's fine .
It plugs into the distributor.

 

[mudboggink5]

x2 I would check the ignition control module first. also check the power wire and ground to the fuel pump.

 

[Chrisblazzer89]

Okay I'll give you the answer to my problem which was the same as yours Try replacing your fuel filter

 

[THISISWEIRD]

Thanks all!