Need some help, I put a new lift pump on about 2 months ago. Runs much better,but it seems to need to crank about 20 secs. when I start it after it is warm (sometimes). Cold it starts fine just after a hard pull (7000lb.50 or so miles) or sometimes when it is warm. FP 15lb so I think lift pump is good. It was at 5lb when I changed it out.

 

check the codes, that will tell you alot.

 

Sounds like bad connections , batt.- cables-ground- or solinoid- maybe up grade with new conntacts in solinoid , but first go to one of the parts houses that do electrical testing and have a load test down on the starter , low amps grd. high starter . whats the history of truck , starter?

 

Try dumping a bucket of cold water on the pump before you start it. Sounds like the VP is wore out.

 

worn out vp44 is not what I wanted to here: If I pour cold water over the pump and it starts right up then it is the I/P ??? for sure ?? Also how long will it last this way?

 

I will get the codes checked on Monday , Is there anything else that will cause this condition??

 

Yes, but we need those codes to start looking.

 

My bet is the VP44. You need a fuel pressue gauage after you get it fixed.

 

Where is the best to get a vp44, or is there an upgrade that is better. I will do the install.

 

cumminsstuff.com is the best I've found. Don't get hasty tho, get the codes and rule out the simple stuff first.

 

Rockwithjason, ok I will go to get them checked in the morning, thanks

 

Hey! Rockwithjason I got the codes checked this morning. p1693,p0234. Thats all I had him clear them. The only time it is hard to start is when it has been run for awhile or on a pull, 7000lbs or so. It never did this till I put the l/p on. I put a fp guage on to check the fp and I had about 5lb. so I was going to go get a l/p but it wouldn`t start till I went and got a new l/p. It finally started but it has done this since then. Thanks for the help BTW it runs fine otherwise.

 

Mike , at one time the ISB had hard starting issues with the vp44 and had calibrations changes that lowered the lift pump press. during cranking. your best bet is have Cummins update your calibration and that will change the pulse width signal to your lift pump. sounds like your new pump press. been causing you problems since you installed the new pump.

 

JohnCA58. First time I`ve heard that, but glad I did. I will talk to a dealer as soon as I get a chance. Thanks a bunch.