Engine/Transmission (1998.5 - 2002) Extended Cranking Problem

[tallrancher94]

Howdy all,
Long post coming. So, I've got a cranking/starting problem. Long story short, when it's cold, it cranks and starts normal. When it's warmed up, it'll crank for like 10 seconds before it fires. There's no fuel going to the injectors in that time. Put a harness that plugs into the back of the injection pump. It bypasses the ECM and starts the engine. Basically, if bypassing the ECM caused it to start normal, the ECM was bad. If it did the crank thing, the injection pump was bad. It still did the cranking deal bypassing the ECM. Replaced the injection pump (DAP), still does it. We warmed it up and then shut it off, unplugged the lift pump, and tried to start it to see if I had too much fuel pressure (18 psi at idle). Still did it. We're at a loss on what to do now. We'll make sure the batteries are good tomorrow, but they were new in February. The engine does crank slow, but the pickup never goes dead. Could the starter be going out to where it takes more voltage to spin it and it's not letting enough power go to other systems? I'm beyond frustrated with this whole deal. Anyone have any ideas or tips and tricks on this? Thanks!

 

[SnoKing]

https://www.turbodieselregister.com/threads/01-hard-to-start-at-times.269961/

 

[Ozymandias]

The classic, your VP44 is probably on its way south.

And 18psi is waaaaaay to much, no more then 12 is good for the sensitive VP44.
Lower that pressure first before you spend any other money onto it.

 

[tallrancher94]

The classic, your VP44 is probably on its way south.

And 18psi is waaaaaay to much, no more then 12 is good for the sensitive VP44.
Lower that pressure first before you spend any other money onto it.

The problem is that it's doing the cranking thing with a brand new injection pump right out of the gate. We tried starting it with out the lift pump running at all and it still cranked for several seconds.

 

[SnoKing]

The classic, your VP44 is probably on its way south.

And 18psi is waaaaaay to much, no more then 12 is good for the sensitive VP44.
Lower that pressure first before you spend any other money onto it.

OP said " Replaced the injection pump (DAP), still does it. "

 

[Ozymandias]

Sorry buddies, I've over-read this little detail.

 

[Nigel]

The pump is unlikely to be new but rebuilt. Did the rebuilder replace the electronics on the pump? I had a rebuild from Scheid Diesel years ago that had the same symptoms and the mechanic sent it back and got another and all was well after that. I did find that when I had the warm start issue I could unplug the temp sensor by the thermostat and the engine would start immediately. I would then plug the sensor back in while running and ignore the check engine light. Better than burning out a starter as well.
Just my 2 cents for what it is worth.
Nigel

 

[tallrancher94]

The pump is unlikely to be new but rebuilt. Did the rebuilder replace the electronics on the pump? I had a rebuild from Scheid Diesel years ago that had the same symptoms and the mechanic sent it back and got another and all was well after that. I did find that when I had the warm start issue I could unplug the temp sensor by the thermostat and the engine would start immediately. I would then plug the sensor back in while running and ignore the check engine light. Better than burning out a starter as well.
Just my 2 cents for what it is worth.
Nigel

Yeah I mean rebuilt. They put all new electronics on. I'll have to try unplugging the temp sensor. Your pickup did the same thing? The guy working on mine looked on the computer program for mechanics and couldn't find anyone in the nation with the same issue. Some similar, none the same.

 

[Nigel]

Yes my pick up and my cab and chassis and another pickup of a friend all suffered the same problem. Our thinking was if the engine always started cold if we disconnected the temp sensor would the pump default to the cold setting, seemed to work. At the time, about twenty years ago most rebuilders were not changing the electronics if they tested good on the bench.

 

[tallrancher94]

Yes my pick up and my cab and chassis and another pickup of a friend all suffered the same problem. Our thinking was if the engine always started cold if we disconnected the temp sensor would the pump default to the cold setting, seemed to work. At the time, about twenty years ago most rebuilders were not changing the electronics if they tested good on the bench.

Did you try replacing the sensor or was that not part of the problem?

 

[Cummins12V98]

Sorry buddies, I've over-read this little detail.

Proves OZY is human.

 

[Nigel]

Did you try replacing the sensor or was that not part of the problem?

Oh yes both of us changed sensors back in 2000. Eventually we found something on this forum that pointed us in the direction of the pump. I’m not saying yours is bad but it’s possible to get one back with the same issue you sent it in for.

 

[BigPapa]

it’s possible to get one back with the same issue you sent it in for.

Yes, it certainly is.