Okay, I am working on a 91 NA that has one hell of a hard problem to cure. Car will idle fine except for a surging that goes away after warm up. While stationary the engine will also redline with no issues. The problem is that as soon as the engine is put under load it falls flat on its face. Almost to the point of stalling out completely. If I'm easy on the throttle i can nurse it down the road but definately not road worthy. I've tried several different things and so far I'm missing the issue. I really hope some one here as delt with this before. Any ideas would be greatly appreciated. Thanks. Steven

 

Pull codes and check for limp mode.

Are there any vacuum leaks? Correct them.

Adjust the TPS.

Make sure the boost/pressure sensor is plugged in.

 

TPS is new and correctly adjusted

There is a code for the metering oil pump. Checked pump. It is bad but haven't replaced yet.

pressure sensor plugged in and working

Have repaired several vacuum leaks but need to smoke it again. I'll get to that as soon as i can.

Thanks for the input. Anything else you can think of?

 

You plan to replace the MOP, right?

 

If you have an MOP code then the car is in limp mode.
You need to fix that like yesterday, or be ready for a rebuild.

Also its an S5, so you will most likely need a new ECU as well.
Usually the bad MOP will burn up the ECU.

 

Yep, if there is a code for the metering oil pump, the car is likely in limp mode.

 

Thanks for the input guys. I had planned on replacing the pump but will jump on that ASAP instead of waiting. Let you know how it goes.

Thanks again.