Odd 6.5 TD problem... help?

[crashandburn]

It's done it twice now. The truck normally runs great (96 Burb, 6.5 turbo diesel). Today I went to start it, and it started kind of hard, the SES light is on and the injection pump is much louder than normal. Last time it did this, I limped it to the parts store and ran their scanner on it. The scanner said crank position sensor. Then I went to show the parts store guy what it was doing, the truck started up like a champ, injection pump quieted down, and the truck has run perfect ever since, until today. At the time I thought maybe it was because I had just bled the fuel line and maybe it needed to cycle a few times, but I tried that today to no avail.

Can a crank sensor cause hard starting and a loud IP? Maybe it is causing the fuel pulse timing to be off???

 

[yellowK20]

PMD could be getting hot and causing issues your describing, I'd look into a relocation kit for it.

 

[crashandburn]

PMD is brand new and relocated onto a heat sink in my front bumper cutout. Thanks though. Just went to parts store and scanned it again. Same thing, crank position sensor. I had to order it, will be here tuesday, which happens to be my next day off.

 

[Fordum]

Those sensors can fail intermittently. Since the engine will not run without one, and can limp along just screwing up every once and a while, I very seldom give them the benefit of the doubt.

Unless it is super expensive, or very hard to replace, I try to put on a new one when I get a code.
One of the few parts that I do that with.

Some engines require major work to replace one, some are easy.

 

[black dawg]

A bad crank sensor can cause this on a 6,5. Without the crank sensor, it runs on a preset injection advance, and the motor sound is much louder.