Hi, I have an Dodge RAM 2500 from 2006 with 5.9 turbo diesel engine, and I am facing a problem, where my engine dosen’t idle. When I am starting my engine it idles correctly, but after few minutes the idle is rough (when motor is warming up). When I step on gas it rews up about 3500rpm and stays there and when I put my car in gear, then it idles correctly. There are no fault codes seen and I have no Idea what to do.Has anybody have that kind of problem or have any idea what might be wrong. I have told from the repairshop, that my ECU might be broken, but I hardly belive them.

3.7 L engine is unusual engine size. Could you give a bit more information on the build of engine you have or maybe a picture of it?But the rough idle could be a air problem where the fuel system is draining back and creating a air bubble. As you rev it up its capable of taking the air and pumping it through but idling its just start to stumble.Being I really don't have any specs for a 3.7L I'm going to have to guess at it a bit.

I have mistyped my car data, sorry. I have had that problem about two years. From diagnostics we checked the gas pedal sensor, that was working correctly. How I could check if there is an air bubble in my system?

When was the last time you changed the fuel filter?

So I can safely assume its a 5.9L Cummins 6 Cylinder (ISB)?If so I would start out with a few basic things like fuel pressure and error codes. Fuel pressure needs be checked at idle and WOT at highway speeds. Both of these things will tell a story about the fuel system and what the problem might be.

Could you, Mopar1973Man, say how the WOT is controlled, I have done the fuel pressure test, and the ECU showed the same data as it was measured from the common rail. Also I have measured the pressure in cylinder from the top of the injectors.

I can't be sure with leaking injectors because when I start up my engine, then there is no smoke coming out and while driving the acceleration is normal.

I have a guess that the FCA might be a problem, but is there any data to check the solenoid?

WOT = Wide Open Throttle (at highway speed)I was just wondering if the lift pump is running low pressure under load causing other issues...