Engine/Transmission (1998.5 - 2002) need advice

[BKOMP]

My truck was running rough and smoking a ton earlier this winter and to make a long story short I had new lift pump, rv275s, and vp44 installed in 4 wks time. Now after a couple 2,000 miles it seems to be doing the same roughness and smoking as it was before. I had a shop in central MN do the work and I have it there now but they can't nail down what it is? Anybody have any ideas. 2001 173,000 miles stock other than the 275s and numerous front end upgrades. Any help would be great. Thanks

 

[JLandry]

Does it idle rough?



If yes, you can hot wire the VP44 so the engine will idle without the ECM being connected to it. If the idle improves with the VP44 hot wired, then it might suggest a faulty ECM... it happens.



For details on hot wiring the VP44, read THIS POST and THIS POST.



A couple other things to maybe look at (clean or replace) are the IAT (Intake Air Temp) sensor and the MAP (Manifold Air Pressure) sensor.



Good luck,



John L.

 

[jjgoss]

is it setting any codes?

 

[madmanmanick]

I am from northern Minnesota, one winter it got really cold and I had a tank full of number 2 diesel. The fuel in my tank completely jelled up one morning. Diesel fuel starts to wax when it gets to 60 degrees. If it gets real cold the fuel will solidify even more. When the tank on my truck jelled up the truck ran real rough. I had enough white smoke to white out a 1 mile stretch of road. I also had the throttle to the floor and the truck would only go 5 mph. The way that I fixed it was to put the truck in a garage and put a torpedo heater under it and cardboard on one side so the heat would heat up the tank. I also added emergency fuel stabilizer. Fuel jelling is a common thing in Minnesota for big rigs that come from out of state and filled up with number 2 diesel. Number 1 diesel has additives to prevent jelling. It may be more expensive, but use number 1 diesel in the winter whenever you can. Hope this helps.

 

[BKOMP]

It does idle rough. When you say ECM are you talking the truck not something with the pump. It's not jelling I run mixed fuel and it will do this even after I drive it then let it sit for a few hours in the cold. It will fill up a parking lot with white smoke that burns your eyes.

 

[HBarlow]

I'm not an expert mechanic but had a MAP sensor go bad on my '01 several years ago. I had been out to the Las Vegas area and was pulling a trailer. It ran fine on the way out there but when I started home it had lost pulling power, would not produce smoke (with RV275hp injectors), and would not develop full boost. It also did not produce any codes.

The truck was still in warranty and the local dealer didn't have a clue. Cummins Amarillo didn't have a clue either. I called Bill Stockard and Joe Donnelly. Each of them independently suggested checking the MAP sensor. I went back to the dealer and told their service manager and the tech and that's what it turned out to be. A new MAP sensor fixed it.

But I did not have a rough idle and would NOT produce smoke when I put my foot in it like it normally would with the injectors. I don't think it is your MAP sensor but it might be the IAT as JLandry suggested. I am not familiar with the symptoms of a bad IAT.