Cummins almost dies when returning to idle?

[JAlford]

My '99 is getting better after an injector problem with Jammer 3's, but lately the engine almost (hasn't actually quit yet) quitting when letting off after hard on accelerator pulls. Not a sudden let off, just gradual and with the clutch in. Rpm nosedives and then comes back up just as quick. Anyone else had this happen?

Jeff

 

[bmoeller]

How's the fuel pressure?

 

[JAlford]

Fuel pressure steady at 13 to 14 psi. Does not drop below 12psi even under WOT with comp on 5x5. I am measuring at the fuel filter canister. I am running my stock filter, fed by the FASS system, which means a secondary filter beyond the FASS. I did this primarily due to wanting to catch anything that was left over from the install of the FASS, and then never eliminated the filter. I still use the fuel heater in the canister this way also.

Thks,

Jeff

 

[DAWG-1]

Brake

Have you checked the back pressure of you exhaust brake? If your break has not been checked in a while, the soot will close it up tight. Sam

 

[DieselMinded]

http://www.dieselpage.com/tip6.htm



DM

 

[JAlford]

Thanks DM - very informative. I will run the stanadyne in the truck and see what happens. Hopefully there isn't a problem, as the rebuilt pump is only a couple of months old and has less than 2,000 miles on it.



Sam - my brake has the cycle pulse at startup feature, and the brake has only been on the truck a few of months. It sounds as if it is cycling properly, and you can watch the solenoid move in both directions without hesitation.

Thanks for the replies.

Jeff

 

[Midnite]

Jeff, mine was acting the way you describe and what fixed it for me was cleaning the battery terminals. I'm guessing I didn't have a very good ground connection.



Mike

 

[Big P]

It might not feel like it but you are letting off too quick. High cylinder pressure will push air back into the hp fuel lines after the vp-44 has dropped back to idle injection pressure. If your truck ever dies, crack a few of the hp lines and bleed it. My 02 used to do it, only stalled 1-2 times, but other times it felt/sounded like it was running on 4-5 cylinders. Wack the throttle or put a light load on it and it was back to normal.