What is the typical response time of an IAC when the load changes, i.e. shift out of gear. How long should it take to bring the rpm back to what it was in gear.
Is the IAC response time programmable, if so how fast can it respond (MEFI 2).

Thanks,
Rick

I don't know that it is changeable. I do know that on the newer engines like the 525 they have an input from the neutral safety switch that bumps the IAC count up about 30 when you shift into gear and drops it back down out of gear. If that input is not there the engines will stall at idle when warm and flare more when it comes out of gear. I'm not sure if they did it on the MEFI 2 or not. If you have a Rinda Diacom you can see the In Gear telltale and also watch the counts jump when it is shifted.

There are several things to change alot of the time we bring it back to idle with negitive timing and spark stableization.

Thanks for the replies.

Tyler, how long should it take for the IAC part to respond with a MEFI 2? I understand the other items but the way it is setup now (I think you have spark stablization active) the response time is 12-15sec. I would have thought the IAC would respond much faster than that not even considering the spark stablization.

Rick

You need to get your Iac counts between 5-20. If your counts are to high then the iac will try to stay open.

There should never be more that 3-5 seconds before the idle stabilizes and much less if everything is working correctly. I suspect you may have build up on the IAC plunger that is making it stick.