Cummins ISX Intermittent lope # Idle

sounds like fuel metering solenoid is going bad.

It is better to change all solenoids..

Any fault codes?

 

Yep, that's what it sounds like too. We had one truck with this, injectors, tune up, filters and so on, still did it. We changed the timing and metering solenoids one by one and it made no difference. We changed all of them and the problem went away, don't ask me how or why!

 

Try firstly befor buying all new actuators swap the fronts to the rear and rears to the front. Doing this can often fix this complaint. Just make sure that you number them all and that you put them in the right places - from the front of engine they go Metering, Timing, Timing, Metering. Give this a try as you may not have to buy all new actuators.

 

Not sure of the price. It'd be best to call your local cummins shop and find out. Or call 1-800-Diesels (Cummins customer line) and talk to them. To answer your other question, It is a simple nuts and bolts job to replace an actuator. They are on the driverside of the engine, under the intake horn.
As someone else has mentioned, the actuators are metering then timing, then the fuel shutoff solenoid in the middle then timing and then metering again, like below.

[M] [T] <S> [T] [M]

 

my truck has been doing the same thing, also appears to be leaking fuel around the fuel filter, but nothing serious. just that after a couple of thousand miles it'll start looking oily.

so much for the solenoids if you gave them numbers it should be

[1m][2t]<0>[4t][3m]

odds being metering and even being time..

so if i'm having the looping problems i should put the back in the front and the front in the back

[3m][4t]<0>[2t][1m] ????

 

Mitch, I wouldnt be as worried about it leaking as I would it sucking air into the fuel at that point. I am assuming you are talking about the on engine fuel filter under your actuators? If so you can isolate if it has air in the fuel real easy. On the left side of the IFSM under the #1 metering actuator there is a compucheck fitting. Attach a quick disconnect fitting and clear line here and coil the line into a bucket. Run the engine at idle no load and monitor for any air bubbles in the line. if you do see any you know it is sucking air. If air is found, I would first check the sealing o ring for the filter to housing and see if it is deformed.
Also your diagram for swapping the actuators is correct.

 

great!!! i appreciate the clarification and info.. off to napa i go.