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JWBTrucking · 03-11-2016, **(Subject: Turbo actuator )**

What should be the measured position on turbo actuator at idle on a 871

Marajin · 03-11-2016, **(Subject: Turbo actuator )**

(03-11-2016 )JWBTrucking Wrote: What should be the measured position on turbo actuator at idle on a 871

That would heavily depend on a few things.

If the emissions systems are still intact and operating, then it will depend on the calibration installed in the engine and what size engine/turbo it has. Stock 400-550 engines usually sit around 60-72%, depending on how much EGR it is demanding into the intake. Bigger engines may have lower positions due to bigger turbos.

If you have the "mandate" removed, and decent custom tuning, then it should sit as low as possible before a vacuum is formed at the outlet of the turbo. (usually 5 - 18% or so depending on model truck, etc. ). Engines do not need boost just to run at idle. This also generally yields about 1/3 the fuel consumption vs the stock positioning.

dbl overdrive · 03-11-2016, **(Subject: Turbo actuator )**

I talked to him today and his turbo position is at 98% at idle witch seems high to me. During regen, it sits at 98% as well. His truck is a 450 and no custom tune. Going down the road, it's around 72 to 80%. Seems high as well.[/i]

snailexpress · 03-11-2016, **(Subject: Turbo actuator )**

(03-11-2016 )dbl overdrive Wrote: I talked to him today and his turbo position is at 98% at idle witch seems high to me. During regen, it sits at 98% as well. His truck is a 450 and no custom tune. Going down the road, it's around 72 to 80%. Seems high as well.[/i]

My old data says 96% at idle.

Rawze · 03-12-2016, **(Subject: Turbo actuator )**

(03-11-2016 )dbl overdrive Wrote: I talked to him today and his turbo position is at 98% at idle witch seems high to me. During regen, it sits at 98% as well. His truck is a 450 and no custom tune. Going down the road, it's around 72 to 80%. Seems high as well.[/i]

that sounds high to me. If the engine is cold, then maybe its in warm up mode, but I would thing it would be lower if the engine is fully warmed up.

A bad exh. pressure sensor can cause incorrect positioning, a bad Delta-P sensor can do it, a bad imap sensor can do it, or it could have a leak, or blockage in a pipe or crossover tube somewhere.

A plugged up dpf or other exhaust restriction can do it too.

The factory engine programming makes it sit in unpredictable positions based on all the data it is being fed. That is great if everything is perfect, but it can be bad if something is not quite right. It makes troubleshooting air and turbo related problems very difficult.

JWBTrucking · 03-12-2016, **(Subject: Turbo actuator )**

That would explain why my boost pressure is not going up past about 30 PSI I will take a look at all of that thanks for your help all of you