I have a 99 dodge 2500 4x4 with 24 valve cummins. When I start it the idle surges between 600 and 800 rpms for approximately 30 sec or so then shuts off. i have replaced the lift pump and injector pump and the computer on the firewall I also have cleaned the IAT sensor stil having the same problem. Several dealerships have looked at it and thats why i replaced the parts that I did. Does anyone have any other ideas.

 

seems like there is air in the lines or a lack of fuel. but you replaced those so how is your fuel filter? have you checked for codes or have a way to check...thats a place to start.

 

Sorry should have said that i did replace the fuel filter and there is no check engine light and when on a scanner there are no codes.

 

Have a fuel pressure gauge? Sure would be handy to know the pressure a the pump.

A little concerned as of why the PCM was changed, the ECU is on the side of the block.

 

i have a fuel pressure gauge i'll hook it up and get back to you. I changed the PCM cause the mechanic at roger williams said thats what he was sure it was.

 

you should have that gauge hooked up for monitoring all the time.

 

I hooked up the gauge and it is showing 10 psi from the lift pump.

 

thats at idle i assume? a bit on the low side if it is... is it a stock lift pump or are you able to adjust the pressure output?

 

yeah thats at idle and yes its a stock lift pump