stalling after hot

[fresburb]

Earlier posts I reported my suburban stalling then not starting after recent fuel filter change. checked the new fuel filter and its clean. What I have noticed since i've been driving it(its's my wife's truck) is the only time it stalls is after it has gotten hot then is shutdown. When I try to start it after it has rested for a while it will start then stall after running for 10 or 15 seconds. It will not start back up until it cools down completely.These are the times i've noticed the trouble. I'm thinking PMD/FSD. I'm trying to get a general consensus. Anybody?

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99 6.5TD suburban 2500 4x4 -stock

[DaveNY]

That was the early syptoms for me when the FSD/PMD began to fail. Have you any CODES ?

[atom_c]

I had a similar problem last summer. It would only stall on a warm restart, usually after it had sat for a bit. I had the FSD/PMD replaced and it still was stalling/hesitating. A new oil pressure switch seemed to do it. It seemed the OPS worked when cold but not consistently when hot. At about $32 it is something to consider.

[fresburb]

Atom and Dave, thanks for the responses. The ses light has not gone on at all. I have not had it scanned. I think the ops would be a good start considering the costs. How difficult is it to replace? Where is it ?

[atom_c]

The OPS is in the rear driver's side of the engine valley, more or less under the fuel filter. Do a search for "oil pressure switch" and you will find plenty of reading. It is not too terrible to replace, bad on the back though.

What would really help is to set up a fuel pressure gauge to see what your lift pump is doing. See what pressure you have while driving from a cold start up. Then see what pressure you get on a warm restart and as it stalls.
Good luck

[rjwest]

96 and latter have a relay,

most lickly not oil pressure sw, it's only a back up for
PCM.

[atom_c]

If the OPS is only a backup to the PCM in the 96+ trucks how would one know if it was failing? Does it trigger a code? Just wondering...