Cm 2350 surging at high idle

[Platinumpete]

Need help! 2014 pete with cm2350 intermediate rough idle and surges at high idle dropping 20 to 30 rpm while surging then quits after a few minutes, also has started stumbling sveral times a day when accellerating also notice priming pump is not shutting off after 5 sec or so like it used to don't know if that matters.engine has 335000 on it .any suggestion for fix is appreciated.

[gearhead]

These are very sensitive to charge flow and egr flow leaks any leaks will cause serging at no load. listen to turbo you will hear it. Also fuel pressure being low can cause this ecm trying to overcome low pressure so pressure moving around could be problem. Without laptop you can check for leaks before and after egr and also boost leaks. But much better to have laptop.

[Platinumpete]

Thames will do.

[JMBT]

Platinumpete: priming pump should stay on for a full minute each time the key is cycled. Shut engine off, turn key on and time it. If it isn't running close to a full minute I would replace it.
On the surging, have you upgraded the fuel pump?

[JMBT]

Gearhead: my 2250 is surging ever so slightly when cruise is set and I hit flat ground or down a slight grade, as soon as throttle falls off. It is barely noticeable. After reading your comment above I check for leaks at all charge air and EGR joints and can't find anything. I am going to hook up Insite while I drive tonight. What parameters should I be monitoring?

[snailexpress]

My truck does it long time. It started surging just on hard pulls slightly then more and more.
Now it surging sometime really hard, sometime not so, sometime not surging at all. Hours driving with monitoring fuel pressure, boost, turbo didn't gave me any strong evidence what is wrong.
BTW the reason could be not even in engine. Vehicle speed sensor, ABS system, accelerator pedal and on........

[JMBT]

Ah, yes. My brother suggested a speed sensor was the culprit as well. Mine doesn't surge at all when there is any throttle being applied. It also doesn't surge at high idle like platinumpete's above. Only coasting when in cruise.....

[jimeneztrans84]

Usually surging has to do with air in fuel system no? At Least that's what my cm2250 was doing. At first is would surge here and there kinda if you presser on clutch really quick. Then kept ignoring it and truck was looking power and shut off. My fuel tanks pick up tubes had a crack on both of them. Could also be fuel pump. I read a post somewhere his cm2250 was doing the same as mine and ended up being fuel pump.

[JMBT]

Interesting....this started on mine after I did the fuel pump upgrade to the new "latest and greatest" two cylinder. No such problem with the old three cylinder hooptie. I have no bad leaks in the system, just did leak down a few weeks ago. 400 psi in 60 sec. also no other symptoms, and the minute I touch the foot feed it is gone.