No boost, replaced N75, still nada

[andynat]

My 96 TDI passat wagon has not had any boost since last winter. Therefore, I have not been driving it much. I did replace the N75 valve. I can hear it click when I try to accelerate. I also have blown into the hose which connects to the ECU and there is no loss of air. I assume I should consider the turbo to be bad????

[Seatman]

Very doubtful, our wastegate turbos are fairly indestructable, I think you might have a bad maf, have you checked it at all?

http://www.myturbodiesel.com/1000q/m...er-fix-TDI.htm

The actuator on our cars uses pressure instead of vacuum too so if you're testing it don't forget it moves the opposite way. The turbo just boosts until it reaches a specified amount at which point the wastegate opens to allow excess boost to escape.

[andynat]

I was able to get my hands on my friends OTC Genesis reader. I went into datastream mode and observed the mass air drawn in "specified" and "actual". There was a large discrepancy between the 2 (actual was much lower). I don't really know where to go from here.....

[chittychittybangbang]

Lots of possible causes, why not help out and let us know what you've changed other than the N75? Start working through the checklist for low power. The MAF thing could be sensor, wiring, turbo, intake clogging, pretty much anything. And blowing into the tube with your mouth isn't a very good test unless you have a calibrated lung. Take the ECU out, check for wiring and hose breaks, take the ECU out and check the hose inside, even the underside of the hose.

[andynat]

It was the MAF, power is now back.....

[ovadshed]

I had the same problem.
To be sure you have boost from the turbo you need a boost gauge.
It is cheap and easy to install.