1995 6.5 T/D No Hot Start

[Aftermath]

My buddy's truck

Cant figure it out. Runs great, but when he shuts it off and immediately crank it back up, no problem, but if he shuts it off and waits 15 minutes, it wont fire back up until its cold. 2 hot batteries, pmd is good. I'm at a loss. It's seems like the computer is not sending a signal.

No codes.

Crank sensor?
Optical Sensor?

Thanks in advance

[DmaxMaverick]

Glow plugs. Repeat the conditions when it doesn't start, but unplug the temp senders (PCM thinks it's -40). Problem is, underhood temp is enough to prohibit a glow cycle, but the engine has cooled enough that it needs it. You can also jumper the glow relay to force a glow. Just not too long, about 8 seconds max, especially if it has old plugs. It is also more common if AC60G plugs are installed, and no accommodation has been made to cycle them longer under some conditions. A manual override is a simple solution (Batt+ power to a momentary switch/button, then to the coil pole on the GP relay). Manually glow more when it needs more.

[Robyn]

How many miles on the injection pump ??

Were the injectors changed recently ???

IP can be getting tired and the plungers are wearing beyond the normal specs.

While the engine is running the flow of cool fuel through the IP keeps the pump cool (cooler).

After shutting the engine off the fuel stops flowing and the HEAT soak from sitting causes the internal clearances to open up some.

It does not take much....a couple tenths of a thousandth extra will cause the plungers to lose enough pressure making ability to keep the pop pressure below the threshold and it will not fire.

Did your buddy stuff in a set of those HI POP injectors ????

On a worn pump these will kill it when things are hot.

Normal pop pressure on the Electronic engines is about 2000 psi + -

On a used pump of unknown condition I prefer a set of squirts that are matched at 1800 psi when changing them out.

Have your buddy leave the hood open so the heat can escape and see if that helps....

WE used to pour cool water on the old DB2 pumps to check for this issue, but I'm not a fan of water on the electronic pumps....

You stated that the PMD is good...

In my experience there are no GOOD PMD's...Just ones that are working at the time, ones that have failed and ones that are about to fail.

PMD is always a suspect in HOT NO START CONDITIONS.

Try a fresh one to test.

IS THE PMD remote located ???

[Kennedy]

Is this the same truck that was running away?

Lack of lubricity pump delivery solenoid is probably worn out. The DS4 is not a bad pump, but you can't ignore the lubricity needs or you get sticking/galling or flat out worn out to where it cannot generate sufficient psi with hot fuel.

[Aftermath]

Is this the same truck that was running away?

Lack of lubricity pump delivery solenoid is probably worn out. The DS4 is not a bad pump, but you can't ignore the lubricity needs or you get sticking/galling or flat out worn out to where it cannot generate sufficient psi with hot fuel.

No, different truck

Going to replace the pump

Thanks !