Turbo actuator position sensor

[Geared_Cortex]

Isx cm871 was giving me inconsistent low mileage no matter what I would do . It was always somewhere around 5 mpg. Playing between 4.7 mpg and 5.2 mpg . Also the egt's where inconsistent aswell. I could not understand what was the problem. Took it to mechanic and plugged it. Then after 1000 dollars bill and still looking clueless . So I did the egr tuneup and changed the sensors and even took the egr valve out to check and still the same problem . So I bought insite from fleabay and reset fault codes to see what happening right now and funny thing is theres no new faults. So I taught the engine was bad at first but it has 400k miles and wasn't burning oil or leaking from anywhere. So I'm scratching my head over this completely clueless until I tried the sensor test on insite and found that I have 0 volts coming from the vgt actuator position sensor . I guess that would explain all the inconsistent egt's and low inconsistent mpg . Correct me if I'm wrong.
But wouldn't a faulty sensor still give some voltage . Could it just be unconnected or it's just dead? Where is that sensor connection and what do you suggest me as the next steps to do this right ? Thanks in advance.

[Geared_Cortex]

Also I forgot to mention that seens I bought the truck back in October it was already like this . And I couldn't know because I'm new to trucking. I worked for someone for about 2 months before I got my own truck and I was driving a very old and messed up Volvo that I don't even understand how it passed the yearly dot inspection with the amount of broken stuff on it . For example the only gage in the dash that worked was the speedometer and rpm , no clutch brake at all . I had to stop the transmission shaft by grinding it. It was so bad I taught my truck was running like brand new when I bought it. I have not found any trusty mechanic yet . I'm live in Montreal city if anyone is from that area and could point out a good honnest mechanic that would be great aswell. Been driving it like this for 15000 miles seens I got it . I hope it's not to bad for the engine. Is there something I should look for specifically in that case ?

[Volvo8873]

What is the rear end ratio on your truck?

[Geared_Cortex]

I taught it was 3.7 at first but it's 3.9

[Geared_Cortex]

If the previous owner had removed the actuator and put it back on without resetting with insite would that make the ecm not sending voltage to it by any chance?

[Lonestar10]

is it deleted? if so did someone reinstall the old turbo that they had replaced with a non vgt turbo with some garbage tuning? if its turned off in the computer i could see possible no voltage other than that computer should be looking for it and tripping a code if its not sending back a reading. does the VGT actuator read any position in insites data log feature?

[Geared_Cortex]

I believe it has the original programming in it. From what I saw on insite. Maybe wrong but that's what I think.

[Geared_Cortex]

It does command positions but there's no sensor reading it's actual position from what I saw.

[Rawze]

(05-11-2019 )Geared_Cortex Wrote:  ...
I tried the sensor test on insite and found that I have 0 volts coming from the vgt actuator position sensor
...

It is normal. there is no position feedback sensor on the VG actuator or turbo. Its feedback position is J1939 data. to see the feedback position, monitor the 'VG position Commanded' and the 'VG position measured' in insite to see if they are less than 2 degrees from each other.

NEXT: if your chasing low fuel mileage and you do not have an after-market set of boost and pyro sensors, your pissing up wind. - A person should know what their truck is doing, and those are 2 of the most important gauges you can have in the dash for monitoring and driving by to save you fuel.





boost gauge: https://amzn.to/2VSSVXb or https://amzn.to/2LASpcj
pyro gauge: https://amzn.to/2HfcEb9 or https://amzn.to/2PVN9yk