I have a 1999 Dodge Ram 4x4 with the 24v 5.9 Cummins engine with over 150,000 mile on it. The truck is a 5-speed manual. The factory lift pump has gone out right about 100,000 miles and was replaced at a dealership with a factory pump. Prior to the pump going out there was a noticable surge when driving down the road at cruising speed. It is fine at idle. There was still a problem with the surging so the lift pump was replaced with a Fass aftermarket lift pump, with the hope of stopping the surge. The surge is best described as driving down the road at a constant speed, and it feels as if you would let off of the accelerator for a moment and then resume normal speed. Has anyone had the same problem and a solution, or even an idea. The Dodge dealerships don't seem to be helpful. They don't seem to have the knowledge when it comes to the Cummins motor. thanks
What is your fuel pressure while cruising? Having a fuel pressure guage is manditory on these trucks, or at least a FP light. If the pressure is coming down when it "defuels" like that then you know it's a problem with getting the fuel to the pump. If your pressure doesn't drop than it's likely in the programming or even more likely something wrong with the VP44 injection pump.
thanks for info There is no fuel pressure guage on it right now. There has been no idiot light on when this occurs. Guess I will have to run to the store and pick up a fuel pressure guage and pod. Thanks a lot. The injection pump was a thought, but just wondering if anyone else out there had the same problem, and could say for sure what it was.
yea man had the same problem with my 99 and it ended up just being a dirty fuel filter. you might want to check it because if the problem continues you can damage the injection pump and that gets real expensive.
yea, the fuel filter was the first thing changed when this first occured. it has also been changed several times since then. thanks for the info though. every little bit helps
hey, forgot to udate you guys. replaced the injector pump and that was the problem. apparently when the lift pump went out it took the injector pump out just enough to cause a problem every once in awhile. when the lift pump was replaced the dealership said the injector pump was okay. well at least it is good to go now.
