Hi guys does my 1999 audi 80 cab have an idle control valve?

[DEVIL666]

And where is it? I have a real problem getting her started when cold? needs a bit of cranking? and she has a spot at 1.5k revs where she just looses all power, then as you rev past 1.5k she pics up again?

Does this sound like my timing is out? she only has 33k on her. The 1.8 engine sounds fine, no stange noises just the 1.5k rev glitch and starting and idling?

Got me beat. Any ideas?

Many thanks

Damien.

[scotty33]

Could be the temp sender for the ECU is goosed, thinks engine is warm all the time, so you get no cold enrichment?

[DEVIL666]

That sounds about right. It has to be electrical? the engine 1.5k glitch is the same every time in each gear? Ecu misreading could be the culprit as you say? Ive spent so much time on this issue, im going to give her to audi this week? im sure it has to kick up a code?

Saying that she still has the 1.5k glitch when she is warmed up?

Thanks mate.

[scotty33]

The long crank times sounds like a temp sender issue possibly. A code read can miss a faulty temp sender, in that a code is logged if the sender is shorted to earth or open circuit. If the sensor is showing the wrong resistance, for a given temp, it is still goosed but will not necessarily throw a code.
I don't know about the glitch, has the battery gone flat/been replaced recently? Maybe a coil pack or some other electrical gremlin, just guessing without a code read. Have you thought of buying a lead from E bay and reading codes yourself? Even I can do it, VCDS lite is free to download, it does fault codes but not all the other tricks Vagcom can do but most users don't really need.
Most Audi 80/cabs need a 2x2 (obd1) adaptor lead as well as the 16 pin (OBD2) vag com lead. Not sure which type the 1.8 cab has?

[DEVIL666]

Thanks so much for that feedback. Its definately electrical? its got me absolutely beaten:1zhelp:. I know there is a possibility that audi will not find a code on wednesday? and then im gona be up pooh creak.

Seen as we have 3 audi's one other 80 cab and my urs6 it might be a good idea for me to get a fault code reader. Will have a look on flea bay!!
Im wondering if it could be a coil on its way out?

Will definately keep you posted on the results on wednesday.

Damien

[DEVIL666]

New train of thought after reading about the ignition system on the ADR 1.8 engine on the cabriolet. I really think the potentiometer might be at fault with the car. ? Any thoughts or experiences guys?

Damien.

[scotty33]

New train of thought after reading about the ignition system on the ADR 1.8 engine on the cabriolet. I really think the potentiometer might be at fault with the car. ? Any thoughts or experiences guys?

Damien.

Do you mean the throttle potentiometer/ position sensor? This is why I asked about the battery, they seem to go out of synch with a voltage loss.
Some cars it can be reset by disconnect battery for a few mins, reconnect, turn on ignition, for 30secs - not start cat and not touch throttle! Turn ignition off. Then start car without touching throttle.
A full throttle body alignment can be done with a registered version of Vagcom if the above does not work.
There could be a fault with the tps, the resistance changes with throttle position, it should either start low and rise uniformly or vice versa not sure which or which pins to test.
some bumph on older 5cyl tps's which may well be irrelevant?!

http://www.20v.org/throttle.htm

[DEVIL666]

Thanks Scotty!!

Yes the position sensor.

You know we bought the car 4 weeks ago and when we test drove it at the dealer it was fine. Then when my girlfriend picked it up 2 days later it was not starting and not idling properly. My guess is that the dealer had jump started her or charged the battery? causing maybe the throttle body to reset itself? so strange when we test drove her she was absolutely fine?

Will try to reset it like you described tomorrow before taking her to audi for her booked appointment!!

Thanks for the link.
Damien.

[DEVIL666]

Ok so 13 faults in the system, turns out the car recons its -30 below, so it is chucking fuel into the engine. hence the rest of the car overcompensating. Audi kept her overnight as once the codes were cleared she would not start. Now they are checking all the electric earths and points.

This is a nightmare. Keep you updated.

Damien.

[DEVIL666]

So Audi say they have narrowed it down to a buggered ecu or a potentiometer? :mad:

ECU 700 pounds please sir

or potentiometer 500 pounds.

Hmm i did say it might be the potentiometer!!

Guys i carnt afford these prices? any one know of a second hand potentiometer for sale for the ADR engine?

Many thanks.
Damien.

[scotty33]

Should not be hard to find, ADR was used in passats and A4 models too


By the way, do you not think this should be the seller's problem? quote the sale of goods act at him and threaten trading standards, if he's not helpful, carry out the threat! If you paid at least part of the cost (over£100) using a credit card, the card issuer is also liable, they will be able to suspend the payment until the dealer sorts things out.

[DEVIL666]

Ok new update from audi.... fitted new potentiometer... still she aint starting? so wiring was checked right up ecu, everything was ruled out. Has to be the ECU now!!!

So getting hold of a second hand ecu, really hope this fixes her. Audi are convinced the ECU is at fault after spending alot of time ruling out every other possibility.

Phoned them this evening to ask if it was possible to reprogramme the imobiliser to a new used ecu? Im sure they can? Otherwise its gona be a fork out for new audi ECU!! :1zhelp:

Keep you posted!!

Damien.

[UR_Acabrio]

So Audi say they have narrowed it down to a buggered ecu or a potentiometer? :mad:

ECU 700 pounds please sir

or potentiometer 500 pounds.

Hmm i did say it might be the potentiometer!!

Guys i carnt afford these prices? any one know of a second hand potentiometer for sale for the ADR engine?

Many thanks.
Damien.

£500 for a TPS !!!! They're avin you over ! mind you thats why we call them the Steal#rs .....
Try searchin Ebay for Throttle Position Sensor in VW/Audi parts, failing that have you tryed a new Lambda probe ?