IAC reset/ ECM
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
IAC reset/ ECM
I just did an IAC reset trying to get my idle right. Followed the Tech Tip exactly. I couldn't drop the idle to 450 rpm without it stalling, and coaxing the throttle to keep it running only made it harder to get it close. So I got it down to 600 rpm. But once reconnected the IAC to the
ECM and reset the TPS it now idles at 720 rpm. Not bad, but my question is, Does the ECM adjust the idle accordingly based on varibles, like knock detection, preignition, etc. Any insight or suggestions ? I'm about to go out and start it and see if it will start with higher rpm and drops with the warm up. ( Oh, replaced the CTS also )
ECM and reset the TPS it now idles at 720 rpm. Not bad, but my question is, Does the ECM adjust the idle accordingly based on varibles, like knock detection, preignition, etc. Any insight or suggestions ? I'm about to go out and start it and see if it will start with higher rpm and drops with the warm up. ( Oh, replaced the CTS also )
Le Mans Master
Joined: Aug 2003
Posts: 9,884
Likes: 3
From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Usually when you set @ 450-550 idle she will stall, get as close as possible then let her stall and start the process... that should get you close... also, check the cable and TB butterflys and make sure there's no resistance or binding that will effect that. Check your timing also (disconnect EST) first...
Don't forget to disconnect battery and reset, then take for drive to reset computer.
Don't forget to disconnect battery and reset, then take for drive to reset computer.
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 898
Likes: 1
From: Pearland Texas
Thanks Vinnie, the idle is holding, after a day of driving. Time will tell. I reinstalled the old Delco IAC. Crappy autozone replacement I guess wasn't cutting it. I would drive to work like I had cruise control on. Sometime 1200-1500 rpm. At least the idle comes down with engine warm up, didn't do that before. I got a new digitla timing light with a tach display, its nice, I can see the rpm responding accordingly. Its so hard to tell looking at the tach in the car.
Le Mans Master
Joined: Aug 2003
Posts: 9,884
Likes: 3
From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Know what you mean... I have a great tech doc that covers it all,,, as i remember, the tech doc here was missing a step in the settings of all (IAC, TPS, Timing, Idle adjustment)... email me if your interested... Works great...
vinnie
vinnie
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
My '89 did the same thing until I cleaned the stock pintel and bore and reset idle. I can't get below 700 rpm warm idle but that's ok with a stick.
