Help low boost

[Mrkentee]

When my turbo got stuck it showed a code. Commanded and actual were different, and stayed the same. On reassembly after turbo install, actuator failed and was replaced. One killed the other, I guess. But it definitely showed a code.

[gonzo1949]

(02-24-2016 )Mrkentee Wrote:  When my turbo got stuck it showed a code. Commanded and actual were different, and stayed the same. On reassembly after turbo install, actuator failed and was replaced. One killed the other, I guess. But it definitely showed a code.

Thanks for the input. I'm lost on this one.

[gearhead]

If it was me i would use calterm and override vgt to see if it moved. Whats hard to beleave is there is no codes. Try calibrating the turbo with insite if there is something wrong insite will let you know.

[gonzo1949]

(02-24-2016 )gearhead Wrote:  If it was me i would use C@ltr!m and override vgt to see if it moved. Whats hard to beleave is there is no codes. Try calibrating the turbo with insite if there is something wrong insite will let you know.

OK gonna attempt it tomorrow. Yeah there's no codes. Other then low boost the truck seems to drive ok

[snailexpress]

(02-24-2016 )gearhead Wrote:  If it was me i would use C@ltr!m and override vgt to see if it moved. Whats hard to beleave is there is no codes. Try calibrating the turbo with insite if there is something wrong insite will let you know.

On the screen shot he posted Turbo commanded is 5%
Turbo measured is 0%
I would run turbo actuato test and check harness on the front of valve cover all the way to ECM. LOW coolant signal could be just short in wire harness and turbo controlling wires in same harness as well.

[Rawze]

(02-24-2016 )snailexpress Wrote:  

(02-24-2016 )gearhead Wrote:  If it was me i would use C@ltr!m and override vgt to see if it moved. Whats hard to beleave is there is no codes. Try calibrating the turbo with insite if there is something wrong insite will let you know.

On the screen shot he posted Turbo commanded is 5%
Turbo measured is 0%
I would run turbo actuato test and check harness on the front of valve cover all the way to ECM. LOW coolant signal could be just short in wire harness and turbo controlling wires in same harness as well.

Thanks for catching that Snail. I looked right past it lol.

Whenever your commanded and measured do not match by a certian amount (maybe it is 5%, I forget.) , the computer will only command it to a small percentage away from its actual position until it sees movement. If it still will not move, it will not try to move it further than that.

I have seen lots of turbos that will only make it to say 45%, but the computer wants it to 70%. The commanded, instead of showing 70, will show only a few percent above or below the measured, where it is hung up instead.

If it were mine, I would drain the coolant and do a thorough turbo and actuator inspection. Also, if you get a chance to bring it bu this way, I can help you with it if you need.

Here is a video on just this...






I saw one last year that was physically locked at 100%. Engine ran terrible. This was a truck without any kind of custom tuning. Factory tuning does not ask for 12% at idle. It showed commanded at 12% and measured was something like 7 or 8%. It was clear that the engine had no idea the turbo was actually at 100% and locked up, but it knew it could not move it the full travel range.

[gonzo1949]

I was watching that video last night and was planing to inspect it this weekend. So your thinking it's the turbos vg ring that is stuck? Would that normally give a check engine?

[gonzo1949]

I ran the calibration test while getting unloaded and it failed.

[gonzo1949]

These are gonna be a pain in the ass