Hi Folks,
I've read a few other threads on here about issues with erratic idle and simtek. I'm having similar problems with mine.
It's a MY99 RB5 with a TD05 16g, newage wrx intercooler, sports cat downpipe, hks panel filter and simtek ecu, manual boost control set at 1.4bar.
I had the ecu fitted a month ago and have the following idle problems.
Starting from cold - The car hunts from 500 - 1500 rpm a couple of times then stalls. I have to give it a bit of throttle to keep it running.

Running while cold - 50% of the time it will be fine and sit at 1500 while it warms up, the other 50% of the time it hunts from 1000 - 1500 rpm.

Starting from hot - If the car has been running and I stop, when I start up again it always hunts from about 500 - 1000 rpm it is a nightmare at junctions and is very jumpy when driving very slowly.

Running while hot - After running it for about 1 min it seems to sort itself out and about 80% of the time it will sit solidly at 900 rpm. 20% of the time it will hunt between 800 and 1000 rpm.

One time sitting in a traffic jam it had been idling fine and all of a sudden started hunting with no touch of the throttle.

I went back to the mapper who spoke to Steve (I've forgot his last name) at simtek and he gave it a bit of a tweak on the rollers, this slightly helped it a bit when cold but has made no difference when hot.
One of the mechanics recommended I soak my icv overnight in wd40 and change the seal.
Is there anything else I can do to try and improve the situation myself before I return to the mapper or is this purely a simtek / mapping issue?
I do trust my mapper, having used him a few times in the past but he is mainly an evo expert, he wants to get this sorted as much as i do so is there any info I can give him that will help?
Cheers!

 

Mine only does it when hot, like yours from about 500- 1000 rpm! There was meant to be an update around the beginning of the year to fix it i think but not sure what's happening!

 

icv needs cleaning or changing?

 

My one did the same since it had Simtek & never stopped. Would go away after warmed up though.

 

I'm having similar issue not cutting out but revs won't come down below 1500 and sometimes creeps up to 2500 any solutions anyone? Tried all the obvious nothing works :-(

 

If you have your Simtek ECU upgraded to Alcatek, you'll find that should be sorted. Assuming you have no other faults, and I'd check for air leaks first, the superior closed loop idle control is a big improvement on the old version.
The turn around for this is much faster now.
Whoever mapped it for you can deal with it, or give me a call if they can't!

 

Thanks Alan will ring Andy Carr tomorrow

 

mine will be updated/sent to alcatek next week, cant wait to see how much better the update will be
thanks martyn/alan for advice

wiley

 

very worthwhile improvement.............

 

On the subject of upgrading Simtek to Alcatel how much is it to do the upgrade and what is the turn around time ? I am based in Jersey so cannot get over to the UK very often so was hoping to upgrade the ecu then come over and get it fitted.