Ok;

I finally have gotten back to my Throttle boody RnR, and I have a couple of questions. I have an 88 S4

1. Driver's side.. There is what looks like a plug for a knock sensor at the end of the fuel injection harness. There is also one that comes over from the other side. I am pretty sure that the one crossing the engine is the one that hooked up to the front knock sensor.

a. there seems to be three mounting points for knock sensors, I only had two installed. AM I missing one???

2. There is a gray wire with a black cap, and three prongs, male.. I have no idea where this one goes. It is comming from the back of the engine in the center. I can post a picture if it helps. Knowing my luck, it will go on the bottom side of the TB.

thanks for the help....

 

possibly goes to the crank position sensor, located at the rear of the V,
if you swap the rear knock sensor with the CPS the car wont run

 

OK, the Hall Sensor was right on for the front.

Here are pics of the connector at the back of the engine. Still trying to determine where this goes.

 

That's a reference sensor that is used with shop equipment that no one has. Not used. You can actually take it all the way out.

 

And to answer your other question there are only two knock sensors.

 

Ok, so what was the reference sensor?

 

cool.... now I dont have to worry. I looked at lots of pics, and it was baffelling. I also looked a a car today, and that plug is bolted to a bracket, and earlier ones have a cap.

thanks for clearing things up. But now all the OCD folks are going to want the reference tool