Hi,

I have a 1994 coupe, AAU engine, AAV (1.3) throttle body and injector, passat elbow and cone air filter.

I had this problem all of last winter, then it has been fine all year.

As soon as the temperature drops to around zero, it has problems starting and especially idling. It will just turn over on the key continuously, if I blip the throttle it starts no problem, however, if I release the throttle it won't idle and dies.

After 5-10 mins of keeping the revs up it idles fine and drives no problems at all. (when it warms up a touch?) Even though it's had a brand new VW blue sensor too.

I think the throttle body / injector / throttle position sensor is to blame, as as soon as you blip the throttle it runs fine. Makes me think theres something wrong with the setup controlling the air / fuel mix on idle.

Any suggestions? I can't stand another winter of sitting in my car every morning revving the tits off it, annoying the neighbours.

Cheers, JJ

Edited 19 November, 201312 yr by poloJJ

You may be right about the starting problem, but the poor idling 'till it warms up COULD be down to the fact that there is only cold air entering the engine due to your cone filter, rather than the air being warmed from the exhaust manifold as it would have been originally. Some people seem to have 'got away' with this, whilst others haven't.

Suggest that you get any fault codes read and cleared, then see if any relevant ones reappear.

Regards.

Thanks for the reply caretakerplus

I may not have been to clear. It idles nice and smooth, even in the cold once it gets catches and idles on its own. The problem is in the very cold it won't catch on turnover without the throttle, and when it does catch it won't idle and stalls.

A blip of the throttle when its turning over and it starts straight away, and runs no problem as long as the throttle is pressed. However, it stalls (won't idle) if i take my foot off the throttle. After a while of fanning on with revs up I can release the throttle and it runs and starts as normal.

It's strange - it starts no problem at 5 degrees C, but around and below zero it just turns over and won't catch without the throttle, and won't idle.

What would I need to get it scanned for fault codes? Someone I know with VagCom says its a OBD 1.5 system and his VagCom won't work?

Thanks

Edited 21 November, 201312 yr by poloJJ

You may be right about it being an OBD, it depends what part of '94 that it was made.

You could try a GENUINE VW temperature sensor, the problem with the non-genuine ones is that some are OK, whilst the next one is duff and if you bought 'the next one' you would probably think that the fault was then somewhere else.

Regards.