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+--- Thread: Cm2350 high commanded vgt (/showthread.php?tid=6762)
RE: Cm2350 high commanded vgt - Carhauler - 02-24-2021
So I changed the egr cooler. Was about halfway plugged. The turbo and actuator looked and felt like new still. I was surprised. Sector shaft was smooth lock to lock. Calibrated and reinstalled.
So fire truck up and after warmup vgt is still commanding high. After warm up commanded goes down in to the 20s, when egr kicks in it goes back up to 85-91%.
Even tried it with the down pipe disconnected. No difference.
Starting to think this is a electrical issue with the egr sensor harness.
Any ideas?
RE: Cm2350 high commanded vgt - Rawze - 02-25-2021
... and what about that durashitter aftergarbage CAC. They are notorious for being restrictive as all h#ell and are known for causing turbo and intake issues.
high position is not unusual.. engine is trying to do a rapid warm-up cycle. - Its that turbo chuffing that you described that is an issue. Is the turbo still cuffing a lot?
also want to ensure the program in your ecm matches exactly the truck and engine... and that the turbo matches too. Might have the wrong exhaust impeller in it if someone has replaced the turbo in its past at some point.
RE: Cm2350 high commanded vgt - Carhauler - 02-25-2021
(02-25-2021 )Rawze Wrote: ... and what about that durashitter aftergarbage CAC. They are notorious for being restrictive as all h#ell and are known for causing turbo and intake issues.
high position is not unusual.. engine is trying to do a rapid warm-up cycle. - Its that turbo chuffing that you described that is an issue. Is the turbo still cuffing a lot?
also want to ensure the program in your ecm matches exactly the truck and engine... and that the turbo matches too. Might have the wrong exhaust impeller in it if someone has replaced the turbo in its past at some point.
Yeah not a fan of the crap on the front. But this started way before that was put on. This truck use to get 5.5-6 loaded 7-9 mpg empty hand calculated. Crazy numbers for a car hauler. Then all the sudden one day just started acting this way.
Turbo isn’t cuffing. Turbo is original. The program matches the serial number and is the newest version. Whole thing is odd. But watching insite, when I notice the commanded positions will spike then fall for a sec. as it does this the egr orifice pressure and differential will increase decrease.
The load percent, intake pressure, exhaust back pressure and any pressure or flow sensor will bounce around all at the same time randomly.
Thing drives me bonkers.
Everything else is great. Just keeps wanting a lot of egr. 10-20% at idle after the new cooler.
RE: Cm2350 high commanded vgt - tree98 - 02-25-2021
Maybe check your air filters and associated piping?? Just a thought.
RE: Cm2350 high commanded vgt - smorgan87 - 02-25-2021
Im confused, is this ur truck or a company truck? I have a philosophy about company trucks. If the owner doesnt give a damn, neither do I! If the owner wants to neglect his $100k piece of equipment instead of fixing obvious problems then why should I bother arguing with him about it. Hell, a buddy of mine about got fired for telling the boss ever few days his cat had a problem right out the inframe shop, BOSS told him there wasnt nothing wrong with the 550 hp cat fallin on its face on the slightest Louisiana hill, said he was just bein lazy and didnt wanna work. Buddy quit after bein told that his 100 hr work week was lazy and the CAT was getting overhauled less than a month later.
RE: Cm2350 high commanded vgt - Carhauler - 02-25-2021
(02-25-2021 )tree98 Wrote: Maybe check your air filters and associated piping?? Just a thought.
Just changed them. No effect.
Maybe it was a update in the program
RE: Cm2350 high commanded vgt - Carhauler - 02-25-2021
(02-25-2021 )smorgan87 Wrote: Im confused, is this ur truck or a company truck? I have a philosophy about company trucks. If the owner doesnt give a damn, neither do I! If the owner wants to neglect his $100k piece of equipment instead of fixing obvious problems then why should I bother arguing with him about it. Hell, a buddy of mine about got fired for telling the boss ever few days his cat had a problem right out the inframe shop, BOSS told him there wasnt nothing wrong with the 550 hp cat fallin on its face on the slightest Louisiana hill, said he was just bein lazy and didnt wanna work. Buddy quit after bein told that his 100 hr work week was lazy and the CAT was getting overhauled less than a month later.
Company. But I take care of it. Boss is old school. Not into emissions trucks.
He cares about the truck. I have a endless budget for customizing And maintenance.
Here in eastern Washington there isn’t much choice besides dealers and bigger corporate shops.
I don’t mind working on it. I get paid for it.
I like taking care of it.
Problem is, company this truck and many of our others came from in Texas, was a large fleet that just runs them to death for 5 years or so then sells them. This one was the odd duck. Only 300k on it 5 years old. Supposedly owner op wanted out. Or maybe it was a lemon. Who knows....
RE: Cm2350 high commanded vgt - Carhauler - 02-27-2021
So, did a little more fiddling around. Let the truck warm up and complete scr warmup mode. After that commanded vgt went down instantly to 15%. Few seconds later it climbed slowly to 82%. Couple minutes later in started commanding egr. When egr started getting to 15% vgt went up to 87-91% fluctuating with egr orifice pressure. Egr differential was around .3-.5.
So I checked dpf differential, it was around .2, dpf outlet pressure around the same.
Ran a regen. Dpf differential started at .74 and ended at .68. Dpf outlet pressure was around 1.3 during regen.
After regen I held the rpms at 2000. Dpf differential is around 1.5 and outlet pressure spikes to 2.3 then settles to 1.7.
For one last whoorah I tried running a scr performance test. Sets rpms at 950 like normal with vgt around 80%, when it starts pulsing the doser a minute later it fails and says
Dpf outlet temp out of spec. Even though it regens perfectly and temps look good.
Even though it failed it continues to keep regening....
Thinking this may be a software issue with my copy of insite though. I remember I had to try over and over to get the test to run.
This morning I checked all the sensor temps cold with ambient and they were all matching.
Going to try leaning dpf differential tubes and tightening all the exhaust clamps and vbands on the dpf.
This thing has me baffled. Thinking it has some weird electrical gremlins or something.
Or it needs riddance of the headache.
Any ideas before I push for riddance? Lol
RE: Cm2350 high commanded vgt - tree98 - 02-27-2021
(02-25-2021 )Carhauler Wrote: [quote='Rawze' pid='62613' dateline='1614225675']
Its that turbo chuffing that you described that is an issue. Is the turbo still cuffing a lot?
And then you said.....
Turbo isn’t cuffing. Turbo is original.
I'm confused...... what problem are we trying to solve here if the turbo chuff is now gone??