wont stat when hot??

[dairieman36]

i am posting for a friend he has a 94 2500 4x4 with a swapped in 6.2 i dont know the mileage he said that once the engine is up to operating temp. it will not start i was thinking it would was the injection pump?
thanks in advance for any suggestions
Brian

 

[snicklas]

Don't these use the "same" DB2 as the IDI? If so it sounds like heat soak. I know there have been a few "testing" techniques in the IDI section, however, they can kill an IP..... Some one else may chime in......

 

[Agnem]

Yup. Sounds like heat soak to me. Typically an engine suffering from this will start fine when cold, but not be able to re-start within about 30 minutes to 2 hours of a shut down. The way to verify this, is sort of like what they did to witches in the salem witch trials. You pour 12 oz of room temperature water on the hydraulic head, wait about 60 seconds and try to start it. If it starts right up, then yes, you have a pump with a heat soak problem, and it is time to get a new IP. But.... if the pump doesn't have this problem, the hydraulic head could seize and snap the input shaft. Hence the reference to the witch thing. It could kill the pump if it isn't broke.

 

[dairieman36]

i didnt know if we should try that or not its the electronic controlled ip it looks like the db2 but with a black box on top

 

[dairieman36]

well tried dumping water on it and it started right up everytime after that so i believe its time for a new ip i cant seem to find an electric on can i just put an all mechanical one on? or will it now work?

 

[u2slow]

Its fairly easy to swap the mechanical IP if the truck is stick-shift. If its auto, the ECM probably won't run the 4L80E properly if it can't "find" the engine.

 

[dairieman36]

thats what i was affraid of its an auto does anyone know where i can get on the ones i have found are all mechanical? thanks

Brian

 

[Dsl_Dog_Treat]

Are ya cooling down the black box as well when yer pouring the water on the IP?
There's a TSB for relocating the black box due to a heat soak issue as well.
But yup sounds like as described above.

 

[Agnem]

I haven't done one yet, but I can probably offer you a "Baby Moose" for your GM product if you need a reliable pump.

 

[u2slow]

You can buy a kit to relocate the Pump Mounted Driver (PMD) to a cooler location and adds a big heat-sink to the unit.

PMDs can also be bought separately from a whole IP assembly (the GM dealers are famous for making you buy a whole new IP and PMD assembly).

The 91-95 trucks & vans that still used a non-turbo diesel w/4L80E had their own ECM that only managed the transmission.

 

[dairieman36]

i believe this truck had the turbo6.5 but the crank broke so he swaped in the 6.2...so if it does have the ECM all i have to do is swap in a mechanical one? thanks mel but i dont know if he wants to spend the money on the truck which is crazy cuz he just rebuilt the tranny and motor