I have a 1994 12v Cummins and I have been having this problem on a seemingly random basis. It happens on long trips and out of nowhere it would start clicking for about 5 seconds and I would loose (about 10lbs of boost but not all power) then it would return to normal for 5 seconds and so on. It would continue this cycle until I pull over and kill the engine. Let it sit for a few minutes, and it would start up again and continue running normal.

I live in LA and was towing my trailer up to Mammoth and was pulling the big grade out of Bishop and it did it. I pulled over, shut it off for a few minutes, fired it back up and continued my way up the hill. It wasn't 2 minutes and it happened again. And again. Until the fourth time and I decided to wait a while. I called AAA to get some cool fresh fuel and I waited for the engine to cool down. AN hour later I was able to continue my trek.

Things I observed:
1. Everytime it happened there was about 1/4 fuel left in the tank.
2. The outside temp was hot
3. This has only happened to me on four occations.
4. Didn't matter if I am pulling a hill or a trailer
5. It acts like the fuel flow is temporalily disrupted, but I can't prove it.
6. Only have 5,000 mile on the fuel filter along with clean air and engine oil.

Because it happens on a randon non-predictable manner, it makes it very difficult to troubleshoot. Any help would be greatly appreciated.

Greg

 

I just spoke to a mechanic and he said it was most likely a wastegate problem. Unfortunatly I only had a few brief seconds to speak with him because his cell phone died.

Does this sound right?

 

Not the waste gate problem. I talked to Banks and they said if the waste gate was sticking open I would have an instant spike in exhuast temps and blowing smoke. Neither happened. Just loss of power.