high idle issue modified rev2 turbo

[jasongtr]

warm idle is 1200-1250rpm

first thing is ive unplugged the ISCV and the idle drops to about 600 or so, so i know that seems to be doing something

ive been to to look for air leaks, cant seem to find one, when i squeeze the one of the large vacuum hoses of the induction pipe that goes under the inlet manifold it will drop alot and look to stall, recovers as soon as i let go of the hose.

Its a rev2 turbo but has a rev map sensor so i assume its had a full rev3 conversion from that point of view, but i cannot see an AIT sensor in the induction pipe (does have a blank for it) ignore that part ive checked and the rev3 map sensor whilst plugged in has no vacuum line to it - it now goes to the link G3 ecu

ive even adjusted the throttle body cable stop thingy and it did seem to drop a bit, but i let it cool a bit (not fully) and started it again and its back up to 1200-1250, the threaded stop is doing nothing now as the top of the throttle cable arm is resting on the body of the throttle body so i couldnt adjust it lower even if i wanted to.

Ideas? if i cannot sort this easily ill break the bloody thing (which was in my mind when i bought it)

asked a mechanic next door to my unit and he thinks the mapper may of set the idle that high, when its up to temp if you turn the engine off and restart it straight away it will sit at 1000, as soon as you rev it a bit even a little bit it will idle at 1200 ish, maybe the throttle body needs changing?

[shinny]

That big vacuum hose you're squeezing is the idle control line - at idle it's doing all the engine's breathing and therefore if you restrict it, your engine will struggle to keep running.

Has the car ever idled correctly with the G3 fitted? Is it possible it's not driving the ICSV correctly?

[jasongtr]

that i cannot say, i bought the car last saturday, im not totally bothered as it could easily be broken for loads more than i paid for it, but now i have it, it does show serious potential as a track car/fast road car - so id like to sort it

the idle valve def does something as the idle drops a lot when unplugged

[bobhatton]

Remove the Link ECU and fit a Rev3 ECU, by far the better one to use

[jasongtr]

well thats not going to happen any time soon

[jasongtr]

im sure this is not the accepted method, but the droning from the exhaust at the current idle is awful.

I have blanking plate from a rev3 turbo ISCV valve that was removed on my old rev3 turbo - now that probably wont fit but it highlights the fact ive owned and ran one without issues without an ISCV valve fitted.

So ive disconnected the ISCV plug and wound the idle screw in a little and it seems happiest at around 1000 revs, maybe the cams and flywheel mean it wont idle happy at 800. Once it warms up it still raises up a little so some tweaking is required.

Ive also email Ryan at 2 bar who mapped it to ask what he set the idle at, trying to get a copy of the software to talk to the Link G3 to see if i can see for myself on the laptop - though that scares me going into that as i dont really want to do anything to the tuning, but a quick peek shouldnt hurt as long as i dont change anything