ABY sometimes not starting

[Henkjan]

I have the following problem with my '95 ABY: after I have been driving it, then shut off the engine for a while, it won't start. there is spark, there is fuel pressure, but it appears there is no signal (at least no voltage measured) on the controls to the injectors. after waiting some time, it will start. does anyone have any ideas what might be the cause of this problem? (no, I have not been able to VAG-COM it)

[Pirvu Eugen]

Fuel pump relay?
Have you check output test?

[GT500]

Cam sensor. when it does its not starting trick, poor some water down the back of the cam pulley area.
It should then start, this test tells you its knackered!
Do a search for changing it,

[Henkjan]

Fuel pump relay?
Have you check output test?

fuel pump relay appears to be OK, since I do have fuel pressure when I try to start

do you mean an output test of the fuel pump?

Cam sensor. when it does its not starting trick, poor some water down the back of the cam pulley area.
It should then start, this test tells you its knackered!
Do a search for changing it,

sorry for the "blond" question (maybe my english isn't as good as I thought is should be): what do you mean with "the back of the cam pulley area"? cam pulley is the belt driving the cam I presume, so this would be at the front of the engine?

in another thread:

Have you checked the MFTS?

could be here as well?? hou do I check? measure electrical resistance? how many ohms should it be?

[Jamo]

It's the hall sensor located behind the cam wheel which needs changing.

Plenty of information on how to change it on here. I did mine when I had exactly the same problem.

[Henkjan]

will this show up as an error if I blink error codes?

[Fat Audi 80]

will this show up as an error if I blink error codes?

Only on the times when it doesn't work!

[Henkjan]

OK, I'll have the light (and the list with codes) ready when I drive the car the next time

(at least feel I can do something usefull now....)

[Henkjan]

Only on the times when it doesn't work!

and now it does start when warm...

bit scary, I bet it will refuse to start when far away from home, late at night, in the rain

[Acidburn]

If the sensor is cheap and easy to fit then could be good to change it if that people are certain this is the problem.

[Henkjan]

wrong side of 100 pound.....

[Acidburn]

Ah ok I see your point, is there the possibility of trying a second hand one if yours starts playing up again? how long do you have to leave it to cool down?

[Henkjan]

I would guess an hour, maybe 2

[Jamo]

wrong side of 100 pound.....

Erm try 60-80 pounds from GSF when ordered as a Bosch part.

Infact the part only cost £30 from Bosch when ordered from a company that is trade.

Or you just change the sensor itself for £5 and drill out the pop rivet and replace it with a nut and bolt with locite.

[Henkjan]

OK. I'll check my Bosch supplier then, I should get 30% as member of the Audi club