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Is it OK to run Multi-Point without an idle air valve?

Posted: Thu Sep 16, 2010 1:00 pm
by JJH
This is for my track car, and we are wondering if it is worth including the idle air control valve in the Multi-Point set-up.
We are using a Sonata manifold with standard (throttle body swapped) plenum; if all it does is help with cold starts, I'm OK with leaving it off, but if it does more than that I'm OK with fitting it up.
There's no way we can use the throttle body implementation of this control valve, so we'd have to make up a custom fitment - which is another reason why I'm OK not to do it.
Also, we are using an Autronic SM4 as part of this project.
Comments/experiences please :D
:beer

Posted: Thu Sep 16, 2010 3:25 pm
by MrBishi
On a track car, leave it off for sure. Only really good for cold starts and bumping the idle up with A/C. You don't need either and save some weight and complexity.

Posted: Fri Sep 17, 2010 10:41 am
by panda
Jeff, I did a MPI conversion on my last rally car & didn't bother with the idle up air valve. I used a Haltech ECU which as progessive fuel richening correction system that is controlled by the water temperature sensor. Its not perfect, but it did start OK every time when cold. The fuel maps eliminated the correction when the water reached about 60 deg C.
I believe Autronic have a similar system. Talk to your engine tuner, if he knows Autronic, he will have the answer immediately.

good luck, panda.

Posted: Fri Sep 17, 2010 4:20 pm
by JJH
Thanks guys.

Posted: Sat Sep 18, 2010 1:52 am
by WANTSOM
Jeff,

What Panda said is spot on. On my track car both the previous Haltech E6 and the current Autronic SM4 used the water temp as the correction for fuel mixture for start up/cold idle and both work a charm.

Cheers
Greg

Posted: Sat Sep 25, 2010 8:02 am
by jakobsladderz
The heater hose connection onto the standard sonata tb is actually used to manage a dashpot type idle speed control anyway. If you can get past having hot water going to your throttle body, the system works fine. That's the only isc I have on my staz and it works well.