CM870 Boost problem?

[B model]

cm870 actuator moves freely and works when tested on Insite. Sensor tests showed normal??
This is a what I would call an intermittent problem sometimes it just drops out and wont boost any. If you are like cruising down the big road its fine, pull off on ramp, when you turn its gone.
It will come back if you drive it a little bit. Is it possible for the actuator air control to have intermittent issues??

[Chamberpains]

Yup, actuator controll modules definitely fail intermittently without a code. You should also have a similar problem on 3rd (high) jakes. It will drop boost randomly.

[B model]

It happened again, it ran great all the way to delivery. Sitting there waiting it started surging a bit and idling bad, I revved it up and no whistle. It is kind of like something is triggering it but no code comes up. I am just trying to be thorough and just not be replacing parts for the sake of replacement. The surging bad idle kinda kicked my brain into the question of ECM?? Thoughts??

[Rawze]

* might be getting air in the fuel?. Cracked pick-up tube in one of the tanks?. Leaky pre-filter housing or supply line?


* Like others have said ... could possibly be your actuator control module for the turbo.


* Is the egr functional on that thing?-- Does it have any kind of custom or delete program in it?. if so, by who?.

just putting this out there as food for thought...
if you suspect the ecm ... start by ensuring it is not in the programming. Might have seemed to run fine before but I have seen tons of bad delete programs for the CM870's out there that people swear run ok until it tears something up. Also with poorly-made programming, sometimes all it takes is a sensor reading a bit off, maybe an altitude sensor, or exhaust sensor,.. etc... unrelated to the fuel, causing the engine to jump operating modes and run like crap because most poorly-made delete programs have no proper engine mode-control re-programming in them and it makes the ecm act up for seemingly mysterious reasons.

[B model]

Its unplugged, and I have owned it since new. This is a new problem started happening about 2 1/2 weeks ago. It was just odd idle at first, I ran the overhead. It runs way better a couple of days and then idles funny again, clean and check fuel and meter actuators, really idles and runs good for a couple days then starts idling funny again and wont boost, I get insite, btw thanks for your help Rawze, start checking all codes except for unplugged code are like 10000 hours old. Also made sure actuator moved by hand and through Insite. It has developed a pattern of when it does it now. It will run great and idle smooth like glass and then I get to where I'm going and generally waiting to unload and after about 15 mins of idling I notice the idle gone to SH_T and I touch the throttle and no boost. It has done this three times, the first boost came back as I was moving truck so next truck could unload, ran great all the way home. The second it didnt come back right away and dropped out a few times coming back a 2 lane road and was out on the road to the house. My Inline6 was delivered that day and I went and got a computer that night and tested next morning, but it was running great super smooth idle and all boost. And yesterday same sh_t ran great and then unloading started idleing bad and I had a bitch of a time getting home as it would come and go and would sometimes not be like full boost but just enough to cruise. And about 10 miles from home snapped out of it and ran great, immediately hooked up laptop and no codes and actuator test works fine. Also it will not boost on first start till it passes 105 psi of air on first start in am, and I cannot remember if it has always done that or not??