Engine/Transmission (1998.5 - 2002) Truck misses except under WOT??

[RedSmoke]

Hi guys-

The neighbor is bringing his 1999 2500 over tonight for me to "take a look at it" (aka fix it for him). He claims the truck is missing on a couple cylinders under part throttle, but doesn't miss at idle or under wide open... .



Any ideas where I should start?



Thanks-

jt

 

[RedSmoke]

Forgot the details!

Sorry-

Forgot to include...



approx. 110,000 miles

(some of it towing 22,000lbs+)

NV4500 5-speed

?"Superchips"? 60 hp chip (for the past 8,000 miles)

no other bombs...



thanks again-

jt

 

[PJStevenson]

I would check his fuel filter. I find every time my truck starts to run a little ruff if I replace my fuel filter it takes care of the problem. Its worth a try. Pat

 

[Souders]

My engine stumbles/misses under load when trying to accelerate

My 99 24v has this problem of engine misses/stumbles at highway speeds when trying to accelerate towing a trailer. Speeds of 55 trying to accelerate to about 65 with partial trottle the engine will miss/stumble until speed is reached. It has been doing it for a long time. Finally have time to fix.



Input appreciated.

 

[Graphic man]

check for codes and see what kind of F/P it has, try the truck with out the super chip, also check the IAT and Map.



Scott

 

[Souders]

Fuel pressure is 15lbs. at idle, 12lbs . at WOT. Could you explain what the IAT and MAP mean.

Appreciate any input.

 

[SMolteberg]

Sorry to say this, but... With my new rebuildt VP44 my truck did just the same thing, mine was worst around 2-6psi boost. Was like this right out of the box. It got replaced under warranty, and with the second new VP it's back to it's glory. No codes at all, and with the old VP and the second VP it's perfect.

 

[Cummins724]

Sorry to say this, but... With my new rebuildt VP44 my truck did just the same thing, mine was worst around 2-6psi boost. Was like this right out of the box. It got replaced under warranty, and with the second new VP it's back to it's glory. No codes at all, and with the old VP and the second VP it's perfect.

I agree..... when my vp44 went bad I drove it home wide open. It shut off if I let the throttle off. Before that I had a miss around 1300-1500 RPM.