ISX surging

Both. Easily seen on the tach, 200-500 rpm sweep most times. I'm assuming you're asking me, if not please forgive me. Just trying to find a solution.

 

There are a bunch of things that can cause this. Do you have access to Insite software? Does the truck run on for a second or two when you shut it down? If so, it's probably a leaky injector check valve. The metering and timing actuators (the 4 relay looking things on the left side of the engine) or check valves can also cause this.

 

Replaced all 4, also 6 new injectors. The injectors have been pulled out at 2 different Cummins shops to check for those things. They've also pressure tested the head. We've tried a new IFSM. New check valves, new liftpump bypass valve, new lift pump, new fuel pump, and more. Starting to wonder if the ECM is failing.

 

disconnect the egr, you will be glad you did, you will love your cummins all over again.

 

I did once, but not sure it was cold enough to have been closed. Perhaps I'll try that again in the morning. Couldn't hurt.

 

It don't matter if its cold or hot - its gotta close when you unplug it coz its spring loaded and needs power to little electric motor to overcome the spring. All this talk about leaving truck overnight is baloney

 

when you go on your trip, disconnect it when the engine is hot or idling erratically. disconnect the plug that is on it's own, I mean not the one that is attached to the EGR. There are two plugs there, one is just hanging there and the other one is clipped or riveted to the egr solenoid.
Fairly easy to change anyways. Take the turbo intake hose off, alternator comes off, drain the cooling system. About an hour or so job, if you want to leave it plugged in. I just changed mines today. Had it for a while kicking around, had to change the water pump so I figured might as well do that while the cooling system is empty.
Being unplugged, your turbo will also work better as well. That's my experience anyways.
Good luck and keep us posted

 

OK, I'll try it again tomorrow and report my findings. The last time I did it, I gained almost a full point on my MPG, but it also derated the engine and made a CEL stay on all the time, so I didn't know if other faults existed.

 

I replaced mine on the road myself - blocked the coolant lines with screws and electric tape around them, you don't have to drop the coolant if don't feel like it. Little rubber caps from mudflaps weights could work too blocking the lines.

I can't believe you replaced everything but EGR Valve. How old the turbo, actuator and air controler is?

 

What do you mean by derate? Lower boost?