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Imteam
07-03-2004, 15:15
My '95 K3500 starts and runs great cold, but at operating temperature if I shut it down and leave it for 1/2 hour or so, it will stall about 15 seconds after restarting. After the stall, if I crank it and pump the pedal, it will restart but runs rough for about another 15 to 30 seconds before smoothing out. After this it is fine.

The motor has only 1500 miles on a rebuild and the same on a new injection pump. I just replaced the PMD and relocated it on a heat sink, but still have the problem. Any suggestions will be greatly appreciated.

Thanks.

tom.mcinerney
07-03-2004, 16:44
I believe 'warm start, stall' is a classic symptom of a bad OPS/LiftPump. To check, put a pressure gage at front-engine fuel filter drain, should be 4PSI+.
There's a chance of involvement of FSD, but the fact that engine runs after start sounds like the internal vane priming pump within the FIP is picking up the load dropped by the LP.

If you haven't yet, be sure to thoroughly clean all sides of all heatexchangers mounted in front of engine. New engines need good cooling, and are worth it.

Imteam
07-03-2004, 16:54
Hey, thanks for the tip. I've already discovered this forum is the best investment in my truck I've made to date.****script:void(0)
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I just checked the lift pump and it is really weak - only about 2 lbs of pressure and it took a few seconds to get that. I'll replace it and let you know what happens.
I'll check the heat exchangers/coolers and the fins. Where I live, it's common to find them plugged with dust, chaff, and or bugs. I hit a grasshoper swarm once in late July and spent hours trying to clean the radiator and tranny cooler in a previous truck. Yuck!
Thanks Tom Mac 95 for your help.