All summer long truck runs perfect, when it starts to get cold out, 40 on down the engine surges like its running out of fuel. Its never died out, it gives you the feeling like the govenor is backing off the throttle then comes back on. Fuel pressure is fine. The truck is an 01 HO 6 speed 3500 4wd with 165,000 miles. Second lift pump original VP. This is only in the winter. I run power service with a lucas fuel additive all year long. I am kinda lost,theres never any codes at all.

 

Any mods to advance timing?

 

i have same truck as you except 2500 and I have the same problem. Seems worst accelerating in 2nd and 3rd, but I also feel it if I'm pulling a grade and lay into the pedal.

 

Mine'll do this too, usually when temps drop below 40 at night and it doesn't get plugged in. Just for a little bit though, I usually run it under 2000 rpm on the flats for a few minutes till it evens out.

Kurt

 

This truck is stock except for 4" exhaust no muffler and air box mod. Nothing else. This does the surging all the time through out the winter. I have reset my apps and it does not make much differance. If I stand on the loud pedal it pulls like it did the day I bought the truck new. My milage is a solid 20mpg on the highway,and 15-17 on my old country roads.

 

check codes??

 

I'm new here but have had this same problem since last winter. I haven't figured it out yet but I have narrowed it down. Mine only has an issue when it's cold and the only for the first 5-10 minutes. Once warmed up it runs fine. But in the first 5-10 minutes I get a dead pedal and my APPS pops two codes. It does this several times leaving me on the side of the road resetting the pedal and clearing codes before it's finally warmed up. I've reset the APPS, replaced the batteries, cleaned the ground connections and even ran additional ground wire from the grid heater. I came to the conclusion that it is a ground issue related to the grid heater. When the grid heater comes on it draws a lot of juice and I think there is insufficent ground and this leads to a voltage spike in the APPS which causes the surgeing. Two days ago I disconnected the power to the grid heater as a test and my truck has run fine so far with no problems. I'm not sure yet if it's the Grid heater relay, leakage in the alternator due to the large draw from the grid heater or a corroded ground I haven't found yet.

I actually joined this forum looking for help also, hopefully someone else here can offer some guidance.

 

HODUALLY, I have the same problems and looking for a fix.

 

I ran mine with the grid heater disconnected and the problem came back. I wasn't convinced that my problem was in the APPS, but, I ran out of ideas so I replaced mine. I got one of the aftermarket ones from Timbo online and it appears to have fixed my problem. The confusing part to me was that I only had issues below 45 degrees and only until it warmed up. The rest of the time it worked fine. Here's a link for the APPS:

http://www.dodgecumminsapps.com/index.html