Audi 90 no spark???
 

Guys please help I am at my witts end. I have been searching all weekend for a sollution.

I just changed the t-stat on my audi 90. I did not remove the timing belt so timing should be perfect besides when she cranks she sounds good. Anyway so when I put everything back together I couldnt get her to start? There is fuel present in the fuel rail. No spark? Ive been told it could be the camshaft position sensor, the crankshaft position sensor, the ignition control module. I have swapped the computer out for a spare that i had. There was no trouble codes either???

Guys this is my family car I cannot afford to be swapping sensors left and right till i find the right one. Does somebody have any suggestions? Any ways I can check theses 3 sensors? Please I need your help.

Thanks, John

You need to tell us what year and motor..

I'd start by looking at the connections at all the sensors you could have come in contact with. make sure the wires arn't damaged and wiggle them to make sure they have good contact.

NH thanks for the reply.

It is a 1994 Audi 90 with a 2.8 v6

I have gone through and checked the electrical and vacuum like 5 times at least. There was no electrical anywhere near where I was working with the exception of the fans for the radiator.

I have replaced the camshaft position sensor
I have measured resistance on pins 1 and 2 of the engine speed sensor and the crankshaft position sensor.

Even though fuel is flowing at the rail I have ordered a new fuel pump relay. If this doesn't work I don't know what I will do. I was told that the fuel pump relay powers the ECU as well as the fuel pump and the injectors so I am hoping this is the problem.

How did you get to the t-stat without removing or moving the T-belt?

No spark indicates a sensor, coil, controller, or wiring problem but I don't know -

Visit the A4 or A6 forum and see if an Audi tech can help

because I'm that good :D

No seriously I had to slide the tbelt forward to get as much play as i could to take the tstat housing off but i never acually removed it.