1800 rpm idle

[DBredS4]

Hi guys, I hope someone has solved this one in the past, I expect so but the search function didn't bring much up.

Anyway, its a 94 S4 with the EBPV removed and the throttle jacking capsule disconnected from the vacuum pump.

Both vacuum pipes ie the one to the EBPV and the TJC are blanked with crimped pipe.

I start the car and it idles right but after a drive and its warmed up the idle settles at 1800 rpm, obviously 800 too high.

I started it again a couple of minutes later and it initially idled right but then cranked itself up to 1800 within a few seconds.

Any thoughts?

Cheers

Dom

[Paul C]

Coming back from Bigsi's handover...

My IAC came loose and the SE idled at around 2000, then went all erratic and stalled

for no reason. The IAC (idle air control) was actually hanging down the back of the engine

by it's connecting wire. The noise that accompanied this event was the sound of the cam wheel

batting the thing around.

Might not be your cause, but was mine and a new IAC fixed it (and stopped the clattering too!).

[DBredS4]

I wonder if thats what I need?

I may just buy one and fit it to see. I will have to see how much they are.

Cheers for the prompt reply btw Paul.

Dom

Edited August 25, 2007 by DBredS4

[Dermot]

As always Dom, 5 mins with Freescan running could check all the sensors before you buy anything, (eg. TPS, IAC, O2, MAP, Baro, coolant). It will also tell you what RPM value the ECU is trying to set.

The desired idle is a also a function of coolant temp, but it could also be the zero reference on your TPS or as Paul said the IAC value need reseting.

Dermot

[DBredS4]

Hi Dermot, good to hear from you.

just need my cable back from Geoff.

oh and a laptop to run it off...

kind of stuffed otherwise, really

As always Dom, 5 mins with Freescan running could check all the sensors before you buy anything, (eg. TPS, IAC, O2, MAP, Baro, coolant). It will also tell you what RPM value the ECU is trying to set.

The desired idle is a also a function of coolant temp, but it could also be the zero reference on your TPS or as Paul said the IAC value need reseting.

Dermot

Edited August 25, 2007 by DBredS4