Intermittent shut down help

[4by4bygod]

Hi All!

A friend of mine is working on a late 90's 6.2 GM pickup for a friend of his. This truck likes to just shut off entirely. It's an intermittent problem, and it can happen when it's idling in the driveway, or just rolling down the freeway. Not a cough, sputter and die situation, but a complete shutoff.

Any ideas are appreciated. the guy doing the work is a school bus mechanic, so the replies can be as technically oriented as you want to get. The owner replaced the injectors, and my friend is trying to diagnose the problem without throwing a bunch of parts at it right away.

Also, any troubleshooting or diagnostic aids would be great, if you could point me to some.

Thanks, Tom

 

[tRustyK5]

I think by 93 or so the 6.2 was done and only the 6.5 available. If your friends truck is 94 or newer there are a few possibilities. Knowing the year would help a lot.

The 94 and newer did have known issues with the PMD and it's location. Not sure if it causes intermittant shutdown though. If it's not a 94 or newer I'd look at the shutdown solenoid on the IP. Other than air in the lines I can't think of anything else that would shut the engine down the way you described. Seeing as it seems random I'd suspect it was electrical. Could even be a bad wire (the big pink wire on our generation of trucks)

Rene

 

[4by4bygod]

Thanks for the reply. It's a 99, I doublechecked.

Tom