Throttle Position 250 E class 2011.

[Davllar_99]

hi all,

does anyone know the right parameters for throttle position, as well as the kpa for inlet manifold? does anyone know what should it be at Idle? I have a feeling the throttle position is wrong, same with the inlet manifold pressure.

attached a picture with the readings below.

 

[supernoodle]

Atmospheric pressure is approx 101kPa, so 100kPa at idle is no problem.
Air flow suggests EGR rate is over 50%, air flow with no EGR I would expect to be approx 16g/s.
EGR flow is dependent on pressure differential, intake to exhaust. You can't increase the exhaust pressure but you can decrease the intake by partially closing the throttle. That might explain why the throttle shows it's not fully open, but I would expect that would cause the intake pressure to be a bit lower.
Of course normally the throttle is fully open, so if off idle the throttle still shows partly closed, that's not right.

Saying all that, don't rely on that OBD data as being completely correct. If the throttle was not behaving you'd get a fault.

 

[Davllar_99]

Atmospheric pressure is approx 101kPa, so 100kPa at idle is no problem.
Air flow suggests EGR rate is over 50%, air flow with no EGR I would expect to be approx 16g/s.
EGR flow is dependent on pressure differential, intake to exhaust. You can't increase the exhaust pressure but you can decrease the intake by partially closing the throttle. That might explain why the throttle shows it's not fully open, but I would expect that would cause the intake pressure to be a bit lower.
Of course normally the throttle is fully open, so if off idle the throttle still shows partly closed, that's not right.

Saying all that, don't rely on that OBD data as being completely correct. If the throttle was not behaving you'd get a fault.

oh right okay, thanks for explaining in more details. tbh, the car doesn't feel right. I've not long ago had inlet manifold changed, car had plenty of power 4 weeks later it went back to normal, very sluggish. wonder if the manifold flaps got stuck.

thanks anyway.