TPS problem...I think...
 

Background: OK working on the '87 944S after letting it sit for the summer with a blown clutch. I swapped on an S2 manifold and all of the appropriate pieces (and there are quite a few.) The S2 ICV sucks, surging badly, but I can deal with that. The S2 manifold I bought didn't come with a TPS, so I reused the one off of my motor. ALL of the other sensors are the ones from the S, including the AFM.

Odd issue: I took the car for a ride (clutch works--what a huge pain in the ass that was) and there's some occasional minor hesitation at low throttle angles. Sounds like a TPS, right? I can feather the throttle and all is right with the world again.

Really odd issue: Is there a WOT switch in the NA TPS like there is on the turbo? The car falls over dead when I go full throttle, but most of the time, if I hold it floored for a second or two, it takes off like it realizes it's at WOT. I've never had a sensor 'wake up' like that with no changes by me. This happens in all gears, and in neutral while stopped.

Other than the manifold and clutch swap, this is the car I drove every day last winter and for more than 20k miles over the past three years.


For those curious, I THINK there's a bit more power and crispness than I remember, but it's pretty skewed due to the time I spent away from it AND by the chipped '89 turbo I'm currently driving every day. ;)

There don't seem to be any ill effects in the low end torque department as the S gears always have you up in the revs...

Thanks

Doug

bump...am I missing anything before I drop money on a new TPS?

My S2 had a serious surging issue when I put the wrong AFM on it. I believe it will look at the AFM and the ICV for airflow. Try the S ICV and not the S2 unit and see what that does.

Does the TPS click?

Bouncing idle sure could be tps, or throttle not closing all the way preventing tps from switching (I did that one when I rebuilt my throttle...).
But I don't think that should cause hesitation.
For that I would start with afm (check signal over its range of flap motion, per FRWilk).
You might even consider checking the ref/speed sensor. If that lies to the dme, the dme might decide less fuel is needed. I mention that because you might have disturbed that when you did the clutch.