The cam position sensor is only used to synchronize the ignition system when you start the car. Once the car is running you can unplug the cam position sensor and the car will continue to run as the crank position sensor and engine speed sensors are all the ECU uses after it sees the first cam position pulse.

 

Yes indeed, I said "crankshaft position sensor", not camshaft.

 

I will check that out.. the crankshaft position sensor. Could you advise on it's location?

And can you tell me what this warning light means? I cannot find anything on it.. not in the car manual.

The light was coming on yesterday while I was driving it.. it comes on when I press the gas pedal and stays on until I take my foot off the gas. I noticed this light was on when I had my fuel pump fixed but I could not address it b/c I had to make the 150 mile drive back home. It is not on all the time but has shown up a few times since.

 

Side Lights/Headlights
--------------------
Crank Position Sensor on a C4:

 

So I have been trying to locate this crankshaft position sensor and I just cannot locate it at all.

According to the pictures.. are you saying it is underneath the car and kind of behind the oil pan?

 

It is on the driver's side of the engine on the block approximately in a plane with the rear pistons. It has a plastic top and is held in place with one hex head bolt.

 

Thank You! I do appreciate it! I will be trying the crankshaft position sensor hopefully in the next few days.

The idle continues to bounce between 800rpm and will drop down to 500rpm and maybe even a little lower. And when I am driving the car it will go but it bogs out and feels like it has very little power. A mechanic I know said a sensor may be it... and that I am on my own with that lol. He did say it isn't or at least likely isnt a clogged cat converter b/c I would not even be able to drive the thing up any type of hill or incline.. which it can.

I did want to mention this to see what you fella think... So I'll drive the car and when I stop.. it starts to smoke but only for a minute and I guess only if I keep it running. I try to trace it and it seems that oil is somehow leaking back and getting on the cat converter and burning off of that. I am not sure how it would travel that far back? Unless it somehow has oil in the cat convert from when I had that oil pressure problem.... But yeah I need to investigate that more.

Here's hoping the crank sensor will fix the idle issue! Thanks again for the help guys and please keep it coming I really do appreciate it.

 

Which sensor should I purchase? There are several options.. Beck/Arnley, Standard, BWD Intermotor... and none of them seem to look exactly the same. I would hate to purchase the wrong one and screw up. And the pricing between them is fairly different also.

1994 Audi 100 CS Quattro

 

Before spending money on the CKP sensor do yourself a favor and SCAN the car... last time when I open my "mouth" in that regard...
"Engine Stalls; does not restart" would be the only "seldom" occurences CKP has any ties with, according to the TSB 24-93-03 (in the Bentley manual).
Your issue sounds different.
The G28 Sensor (Engine Speed/RPM sensor) would be more likely linked to the idle fluctuation and bogging down.

 

I agree, or the temp sensor.