NEED IMMEDIATE HELP PLEASE< random igntion dropoff now I can barely keep her running

[Beechwood]

No new codes present. I will check the grounds when I am out of work. I have a hard time believing power washing the motor didn't cause this to surface, since the problem emerged immediately after I did it. I have great spark off the coil.

This video shows the sputtering and the fuel gauge jumps a few times. The speedo didnt move this time.

https://www.youtube.com/watch?v=Gimb9ReskcM&feature=youtu.be

The SES light blinks on same time as the fuel gauge jumping... weird.

It sounds like the timing is waaaaay off.

 

[SunlitComet]

WOW. I was going to recommend you try a used ICM because of the way the tach is acting but seeing as the fuel spikes when the cel illuminates and hearing what sounds like detonation I would recommend your try a spare 98-99 similar setup pcm if you can find no damaged wiring from the pcm to to engine bulkhead connectors.

 

[Beechwood]

I put new ICM in. I know it could be bad new..

My buddy has a 1998 chevy truck with 350 vortec. Do you think that his PCM could be used to at least make it run (if the PCM is indeed the problem)??

 

[hosseface]

I put new ICM in. I know it could be bad new..

My buddy has a 1998 chevy truck with 350 vortec. Do you think that his PCM could be used to at least make it run (if the PCM is indeed the problem)??

What trouble code does it have stored? Specific code #

 

[Beechwood]

It doesn't have any codes. THe ses light blinks on and off (when I can actually get her to run) but everytime I check... no code.

 

[Beechwood]

Cleaned all grounds, Tried another PCM, condition stayed exactly the same. I am going to change all plug wires and plugs as they got very fouled out with the misfiring, and if that doesnt do anything, I will look into the timing chain.

 

[Beechwood]

Changed spark plugs and wires. Fired up and idled fine for about a minute and a half, then quit. Back to sputtering and barely running.

I am bringing this ***** to a mechanic. I am stumped.

 

[SunlitComet]

Have you tried monitoring fuel pressure when this happens?

 

[Beechwood]

Solved!!!!

Mechanic found a break in the wire between the Crankshaft sensor and the PCM. He had to trace it back from sensor to PCM to find the trouble spot. A literal needle in the haystack.

Thanks to all for your help!

 

[99Vortec]

Thank you for sharing that. Did he (Your Mechanic.) say if the break was close to the crankshaft position sensor? Or was it further upstream?