Auxillary air valve on 5 cylinder - Idle problem

[Darron Edwards]

I,ve recently had trouble with my tick over on my ur quattro. I checked and then changed the auxillary air valve but the problem still persisted. The tick over would be too low when cold and then too high when warm. No adjustment of the air screw would sort the problem so I checked the auxillary valve and found that it was only partially closing. I swapped the valve without success. I later found that there was a partially burnt out connection on the back of the fuel pump relay. Because the relay powers the aux valve and warm up reg, it was causing a current drop through to the warm up regulator and hence the auxillary air valve. Once I had cut the wire back and fited a new female spade connector, the correct current was reaching the heater element in the auxillary valve and resulted in the bi metallic strip operating fully to close off the air valve. She now ticks over perfectly.....I hope that this information will be of use to somebody.

[Lofty]

Originally Posted by oldsynth

I,ve recently had trouble with my tick over on my ur quattro. I checked and then changed the auxillary air valve but the problem still persisted. The tick over would be too low when cold and then too high when warm. No adjustment of the air screw would sort the problem so I checked the auxillary valve and found that it was only partially closing. I swapped the valve without success. I later found that there was a partially burnt out connection on the back of the fuel pump relay. Because the relay powers the aux valve and warm up reg, it was causing a current drop through to the warm up regulator and hence the auxillary air valve. Once I had cut the wire back and fited a new female spade connector, the correct current was reaching the heater element in the auxillary valve and resulted in the bi metallic strip operating fully to close off the air valve. She now ticks over perfectly.....I hope that this information will be of use to somebody.

Thats interesting stuff.....Moneypit suffers from that niggle.....know where to look and investigate.

[Darron Edwards]

Originally Posted by Lofty

Thats interesting stuff.....Moneypit suffers from that niggle.....know where to look and investigate.

Exellent, I hope you fix it, Daz

[msh]

Originally Posted by oldsynth

No adjustment of the air screw would sort the problem so I checked the auxillary valve and found that it was only partially closing. I swapped the valve without success.

This doesn't mean anything, as u found out

[quattrokid]

i had a split on the turbo to metering head hose which was causing me all sorts of running probs, its hidden away under the air box so not easy to find it.

[Darron Edwards]

Yeah, small faults are the hardest to sort out. On my car, because the aux valve was only closing 75%, tick over was still high, I did the old pinch test on the aux valve hose which told me it wasn't closing even though it would close when connected to a battery on the bench. Current drop was the culprit.

[kerker21]

hmmmm iv got a tick over missfire on my old girl to ,it sounds like its droping onto four when ideling but a slight touch on the throttle to pick the revs up by a mere 150 rpm and it stops and back onto all five iv changed plugs leads dizzy cap and still no joy im thinking slight air leak but not sure as carnt hear air leak on booste , any ideas ?????????

john...

[Darron Edwards]

Originally Posted by kerker21

hmmmm iv got a tick over missfire on my old girl to ,it sounds like its droping onto four when ideling but a slight touch on the throttle to pick the revs up by a mere 150 rpm and it stops and back onto all five iv changed plugs leads dizzy cap and still no joy im thinking slight air leak but not sure as carnt hear air leak on booste , any ideas ?????????

john...

Sounds to me like a slight air leak there John, have you checked the injector seals....spray some WD40 around em when the engine is running, if the engine note changes....its sucking in air there.

[kerker21]

already beat you to that one darren had them out today to check if plastic inserts had unscrewed but no fine , iv checked for air leaks by presurising the system from elaphants trunk on but only used 3o psi from tyre so will try compreser on saturday , have considered low voltage as volt gauge in car only shows about 13 volts on tick over but iv got a spair aultinator , any thaughts ????

[Darron Edwards]

Originally Posted by kerker21

already beat you to that one darren had them out today to check if plastic inserts had unscrewed but no fine , iv checked for air leaks by presurising the system from elaphants trunk on but only used 3o psi from tyre so will try compreser on saturday , have considered low voltage as volt gauge in car only shows about 13 volts on tick over but iv got a spair aultinator , any thaughts ????

one other thing john, Check the connection on the fuel pump relay, you may have a voltage drop at the pump....just a thought.