Engine/Transmission (1998.5 - 2002) Injector pump

[cmills]

Tell me what you think, My truck starts right away in the morning after it has set and cooled down, but if you try to start it after it has been up to operating temperature you usually have to crank it a lot longer, yesterday I was pulling a trailer around all day and the last time I went to start it it took about 5 min to get it started by the time I let the starter cool down a couple times because I cranked on it so much. I went out this morning and it started right up, and it also did pretty good today, but it always starts harder hot than cold. I checked the lift pump pressure and it is good so all I could think of was the Injector pump. By the way the truck has 191,000 miles on it and it is the original pump.





thanks for any info,



Cory

 

[Gary - K7GLD]

Try looking at THIS:



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=75504&highlight=hot+starting

 

[cmills]

Thanks Gary, I went to Scheid diesel and they said it sounds like the pump, I'm taking it in the 19th to get it check out. They said they rebuild the pumps now and they will have one there if that is what it is and they can have it done in a day if they don't have any prolems.





Cory

 

[rashwor]

That is exactly how my VP44 went out with 136,000 miles on my truck. Replaced it with a new VP44, and it has started like new ever since. Hard start when hot was the only problem I ever had with mine and the first start of the day was always like a new truck. But subsequent starts during the day were long drawn out episodes (10+ seconds cranking). I never had any codes set.



Good luck, keep us posted.

 

[cmills]

Thanks Rashwor,



One other question, could a bad injector pump cause a decrease in fuel mileage, just curious.



thanks, Cory

 

[Gary - K7GLD]

Shucks - I'd not complain if I got 136,000 miles outta my VP-44 - it took me 11 years to put 120,000 miles on my '91 - then I sold it after buying the '02...

 

[A Johnson]

Originally posted by cmills

Thanks Rashwor,



One other question, could a bad injector pump cause a decrease in fuel mileage, just curious.



thanks, Cory

I think it is possible, but it is kinda wierd logic.



In the 1980's and the day of the PT pump on the 855 engines people would see increased mileage with hopped up pumps, the reason is they could stay in higher gears longer on grades or not shift down for short grades. This allows total RPM's per mile to be less than with a stock pump. Seems the total RPM's per mile had a bigger effect on fuel consumption than the increase fuel per injection event. So by this standard if your pump is causing low horse power it could also decrease fuel mileage. Also if injection timing is not optimal due to a defective pump it could cause less MPG I would think.



A Johnson

 

[rashwor]

Cory,



I guess it could, but in my case the mileage never changed. I have never heard of it happening to any of the 24Vs on here. Good luck!



Gary,



Sorry for complaining. I am happy that I got over 100k on the first pump. I am happy with any injector pump that gets over 100k! I would be ticked for any pump that did not make it to 100k.



FYI... my old '92 has over 240k on the original pump but we are talking two different pumps.