Archived Really, Really Hard Starting

[WileyCoyote]

My 2001 HO 6 speed became really hard to start hot or cold around the first of November. It did the same thing last year. If the truck sits for about 30 minutes or more, it starts only after a long cranking period or a long run of the lift pump. The problem seems to appear with the arrival of winter blend fuel at the pump.



The Cummins TSB 18-015 that was applicable to my engine addressed this problem with a reflash of the ECM to reduce voltage to the lift pump to prevent cavitation (bubbles in the pump output due to overpumping action) of the winter blend fuel. The Cummins hot line said the reflash would do the trick.



It did not help. The truck is still just as hard to start. It resembles an out of fuel situation inside the VP44 which is only overcome by the lift pump running for a long time and priming fuel tthru the VP44.



There is no evidence of fuel leaking anywhere either running or stopped.



I posted an earlier similar thread, but now that I know the reflash did not fix anything, here I am again.



Anyone have any suggestions?



Thanks,



Harry

 

[WileyCoyote]

Cummins Said---

UPDATE: I talked with Cummins and they said the problem now appears to be that the fuel is draining back out of the VP44 possibly other parts of the fuel system including the filter.



This is why the lift pump has to run a long time to reprime the system before the engine will start.



The question now is how many places either on the engine or chassis might be contributing to the problem. I know that the banjo bolt on the VP44 return line has a check valve that might cause the drain back if it does not seat properly.



Are there any one way check valves elsewhere, either on the pumps or on the chassis lines to the tank?



Thanks for the help?



Harry

 

[Bigstick]

I hate to tell you this but your truck is doing the exact same thing mine was when my VP-44 was bad. The best thing to do is this, get a FP gauge and hook into the check valve at the vp-44 cycle the lift pump and you should have between 12-15 psi. If you don't then your LP is bad, if you do then your VP-44 is bad. If your LR is ok the way to start it is to crack open the #1 and #3 injection lines. and keep cycling the lift pump by bumping the key until you have fuel at those lines. THen you will have to crank for about 45 seconds straight and it should fire up. THe truck will run fine as long as it is running but as soon as you shut it off it will not restart. A little Ether will help too but not too much. I got mine replaced under warranty even with my mods, I just had to take them off before going to the dealer. A new vp-44 is 1400 for an ETC motor and 3200 for the ETH motor. My vp-44 went last month went my LP went out, then just last week my head gasket blew with only 30000 miles. I love this truck but this is gettin ridiculous.

 

[mikel]

I don't know about the pump being bad or not, thankfully I haven't had to deal with any of those issues, but I do know that at least one vendor Piers Diesel lists the H. O. pump for about $50 more than the non-H. O. (about 1400 for the H. O. and less than that for the non-H. O. )



Just so you know.



Mike

 

[brandonwhite]

https://www.turbodieselregister.com/forums/showthread.php?threadid=61031



Sounds like we were having the same problem. Mine turned out to be the VP44

 

[WileyCoyote]

UPDATE

UPDATE: I measured the lift pump pressure both during the start mode and with the engine running. Always at 15 psi before start and 12-15 psi with the engine running.



When you shut the engine off, the pressure bleeds to zero in a matter of seconds. Is this normal, as there is a small bleed orifice in the banjo bolt for the return line, or is it bleeding down too fast?



The problem seems to be that the VP44 is losing prime and only when the lift pump runs for about 15 seconds or more will the engine start. This is after sitting for about 30 minutes. The truck will start right away after shutdown. I plan to try to start after various waiting periods to try to characterize how long the bleed down and deprime take.



My next move is to negotiate with a dealer for warranty on the VP44, but I expect a hard time. Any advice as to the proper buttons to push with describing the problem?



Thanks,



Harry

 

[brandonwhite]

I walked in to the dealer and told them my truck was hard to start. I told them I thought it was the lift pump but that I did not know for sure. The starting problem was obvious so the could not deny it. They called me a few hours later and said the LP was good but the inj pump was bad and new one was on its way. I should get my truck back in a couple hours so I will let you know how it goes.

 

[pwr2tow]

The bleed down to zero pressure after you shut off the truck is normal, mine does it in a few seconds (slowly goes to zero).



What ever you do, do not use ether, these engines and there upstream components are not the same as the old tractors of yesteryear.



If you have lift pump pressure of 12 or better as soon as you bump the starter then I would tend to believe it is the injection pump that is bad. Most times the truck will start almost right away even if the lift pump is bad, the reason is the injection pump has an internal pump in itself and can pull fuel to itself, the lift pump is there to help the injection pumps internal pump and to help keep the injector pump liveing longer by increaseing fuel to the injector pump for lubricity. I think this is what I have been told.



Ron

 

[Ron Bissett]

Ether + Grid heater could = Boom . Thats a no no :-{} Ron in Louisville KY

 

[jerryrigg]

From the service Manual



"If a Diagnostic Trouble Code (DTC) has been stored for “decreased engine performance due to high injection

pump fuel temperature”, the overflow valve may be stuck in closed position. "



"The valve opens at approximately 97 kPa (14 psi). If the check

valve within the assembly is sticking open, fuel drainage of the injection pump could cause hard starting. "



The code is P1180.



-Matt