engine wont restart when warm ?? sensor fault?

[JJmac]

Pulled into a service station for fuel and the car wouldnt restart - so i left it for 20 mins then it fired up first time - this is third time this happened recently - anyone else have similar problms?
Im thinking it must be a temperaturer sensor fault making the computer think the engine is too hot , so kills the ignition until it cools down to about 70 degrees. Coolant levels are OK.

If so - how much is a sensor ? and is it difficult to replace?

cheers.

[SimonS4MTM]

Does it run and then cut out, do your dash lights and DIS come on as expected?

[JJmac]

Dash lights and displays come on as normal and no faults are displayed.
Its only when i turn the engine off after is been running for a while and then try to restart it sometimes wont fire up until it has cooled down. The engine hasnt cut out as a result of the fault .

[GardinerG]

Does the engine turn over? if not then the only time I have seen a similar fault is when the starter motor is shot or it's heat shield is missing (gets too hot from the running engine). Had this on a Golf and seen it on a 209. Dunno if that is your problem, but the engine won't turn over at all if this is the case.

[JJmac]

The engine turns over ok - it just doesnt fire up - thats why i thought it was a electrical fault stopping fuel flow to the engine until it cooled down again.

[GardinerG]

Do you know anyone who can do a fault scan using VAG-COM or similar? Might help.

[JJmac]

think i will have to take it to the local garage and let them have a go at it.
I warped the discs driving across germany a few weeks ago and i have been told that its not a good idea to have stock discs skimmed. anyone know of a good place to buy from?

[UKS4APR1]

Pulled into a service station for fuel and the car wouldnt restart - so i left it for 20 mins then it fired up first time - this is third time this happened recently - anyone else have similar problms?
Im thinking it must be a temperaturer sensor fault making the computer think the engine is too hot , so kills the ignition until it cools down to about 70 degrees. Coolant levels are OK.

If so - how much is a sensor ? and is it difficult to replace?

cheers.

Hope you got this sorted, if not it's probably the coolant temp sensor - it's a common problem and there is an improved (green coloured) version to replace it. Easy to do, ECU thinks engine is cold and overfuels. It's a 4-pin sensor, the other 2 pins are for the temp gauge on the dash.
Get it here....... https://sslrelay.com/s74326199.oneandon ... 9501A%3D29

[jb7_uk]

had exactly the same thing on my old W-reg (facelift) A4 2.8Q.. as above.. new sensor sorted it right out.

[JJmac]

I finally got round to replacing the temp sensor but the fault was still there. Had it checked out on the computer and a crank shaft sensor was throwing up a fault. Has anyone had problems with crankshaft sensors ?? , the engine starts fine when its cold and when its at full running temp(90) but when i leave it off for 10 mins after its had a long run it doesnt want to start - Does this sound like the crankshaft sensor is about to die? is it difficult to replace?

cheers.

[Harper--D]

Had similar problem on the S2, hall sender was knackered. Quick fix was to chuck water on the sensor and it started fine!!! Got sensor replaced in the end!