Thread: idle has sucked for years, any way to tune out the iac completely?!?!

like the title says, ive never been able to get the idle to act correctly no matter what. always bounces around horribly, while coasting if I depress the clutch the car will often die and if it does, horribly bounce around yet again. is there a way I can completely tune out or delete the iac for starters? im sure theres more going on but ill save that for another day as im tired of trying to sort this issue!

and yes ive read all of the idle threads made thus far, still nothing

If you really looking for feedback you need to be very specific about your mods, all scenarios when this happens, last tune up dates, it could be a simple cleaning of throttle body, when was the last time you took apart egr and unclog it , what are the voltages on tps?, maf?, when was the last time you set up your timing? On crank and dizzy ? Harnes on maf and tps ok? You need to unfuck yourself from this issue by simply specifying and start cancelling out and narrowing the issue

Ben has a great write up on the idle control system here: http://www.sr20-forum.com/information-library/50162-ins-outs-stock-idle-control-system.html

I can't help but wonder though if you have some other issue with your engine that is causing problems, distributor, injectors, plugs, unplugged vacuum hose, etc.

shoot me a message on facebook, i have really good idle stabilization parameters I will share with you.

but yes, you can delete it but you will need to tune your throttle body screw and possibly your throttle cable very precisely and then compensate for the TPS voltage being slightly out of normal operating range. This will throw off your cold start but its what i do on race engines i work on.

You can delete it, but better yet would be to take a few logs of the issue and post those and your TCD and I am sure we can help get you squared away!

its the tune for sure. many of those items have been taken care of long ago, and this hasn't started until I went nemu. idle was rock steady before. there have been times where I can stable the idle out and it would hold for some time, but it then falls victim to its old jumpy ways.



will do, I adjusted the tb and it helped for a little while, but then the issue came back. id love to have it solely idle off of the tb, but they car will not start once I have the iac unpluged



will do, ill send some emails with the info. I know its something tune related. im very familiar with nemu, but I think this is something that is outside of my knowledge or something im simply not seeing

OP brings up a dumb question I've always wondered.

Sometimes when it's humid/raining outside, when I start up my 98 SE-R, idles fine until I get off the clutch pedal, then idle promptly drops and dies. Why the clutch pedal?

To answer your question storm, when depressing the clutch, you are putting less load on the engine. When you let up the clutch, the iacv duty % raises, to cope with the additional load.

There is also an idle boost during clutch in. This achieved by looking at the clutchpedal switch.

Why your car only does this when it's wet is another mystery...

Cool, that answers the question.

But yes, it sometimes runs like absolute shit when its raining outside or really humid. Idle goes from 500 to 2000RPM over and over and over until it warms up.