24 valve max 1300 RPMS

[Dave R]

CHANGED fuel filter and lift pump 1998.5 ram 250 24 valve idles at 850 RPMS
max 1300 RPMS when push throttle .

 

[cerberusiam]

Check for codes but VP-44 is likely toast.

 

[Layne Merritt]

Dave R, what was the result?
I got my truck out last weekend after a (southern) winter sit with a battery maintenance charger on. It started great and about two miles down the road the CEL came on and now it won't go above 1400 rpm. It starts and idles fine. Codes: P1689 with the P1693 companion code. I confirmed continuity of the wire harness between the ECM and the VP44. The plugs at both locations are clean. I don't want to replace expensive parts without a confirmed kill.

 

[DonFitzwater]

Just put a pump on it.

 

[cerberusiam]

Codes: P1689 with the P1693 companion code.

VP44 is Tango Uniform.

 

[Layne Merritt]

Yes, I suspect so. I finally found a Youtube video demonstrating the exact symptoms. All other descriptions didn't match exactly. I ordered a VP44 from Thoroughbred Diesel. I will post an update when I get finished.

 

[Ozymandias]

Just to be sure for the new VP44 - your lift pump is working properly at the desired pressure and flow?
Check that if you haven't already, other wise your new VP won't last long.

 

[Layne Merritt]

Yes, thank you. I replaced the lift pump some years ago and also installed an after-filter pressure gauge; everything there looks good.

 

[Layne Merritt]

Update: I finished replacing the VP44 tonight and all went well. I took it for a short test drive and everything seemed normal. I will take it for a longer drive tomorrow and get the codes cleared.