Nailed that Idle

[timothydog]

Ben,
Don't worry about the idle.
That screw is not an idle screw. It is a throttle set screw. There is a difference. When your IAC and TPS are set optimally the car should idle where the chip intends it to.

Rick,
When you have a big a big jump in IAC like that you want to make sure your TPS is set. I had to stop in the middle of adjusting the IAC to set the TPS because the voltage was .50 at idle and was causing the engine to rev and throw off the IAC.

 

[NICKG]

what about a thrasher chip,,,it idles in open loop!

just put in my jj modded throttle body, and my iac counts are near 60, tps is solid at .48v car idles nicely. but....i know the counts are high, any have this problem? it does not seem to go down much by adjusting it. i should say i installed a power plate at the same time also.

 

[bar87]

Originally posted by Bens87tr
When I was doing my IAC adjusments today, whenever I tried to lower them the rpm's would go up. I can't get the idle down to the 750 rpm like the extender chip is programmed at. What gives?

you arent going by the factory tach in the dash are you?
they suck. my car idles at 1250 rpm but my scanmaster ays 750

 

[Rick]

I was re-adjusting the TPS after every time I turned the set screw 1/4 turn. A few times I didn't need to because it was still in range. Now I get to do mine. Very easy with Turbo-Link.

 

[Bens87tr]

I was going by scanmaster for RPMs. I got the IAC down to the 15ish level and the TPS a .44. It idles in the 800 range, a little higher than the chip is programmed for. I'm going to post in the chip section for a little help getting the BLMs right.

 

[turboaddict2]

Hey Rick after you adjusted the iac and went to re-adjust the TPS was the engine still running or did you turn it off then adjust the tps?

 

[TurboJim]

Originally posted by Rick
DONE!!!!!!!!!! One thing though. I was keeping it running while doing all the adjustments. It went from 100 down to 48 when I decided to turn it off and restart it. When I restarted it the IAC was then down to around 16!!!!!!!!! Can't complain but I was wondering what would have happened if I wouldn't have turned it off and restarted. I checked it 3 times later and it is hanging in there. No more dying when he lets off the gas. Also I took the previous advise and pulled the TB off and cleaned it.

Thanks as always guys, you got me through another one

As you lower the idle screw, the ECM see's an idle underspeed error and compensates. Then you drop the TPS and it goes into negative %'s. Once you have min air set right, and TPS set right, and cycle the key (or just stall the car) the ECM reboots and the new TPS value is used for 0% throttle and the IAC re-parks at 120 or 96 or whatever counts are set in the calibration and the ECM brings them down to achieve the right idle speed.. Since your car didnt need the added air this time, IAC dropped to 16 because thats all the extra air the ECM needed to control the idle.

 

[Rick]

Nope, I only turned it off the one time after many back and forth setting the IAC screw and idle TPS. Looks like it needs to be restarted after resetting both of them. It definitely solved his stalling problem and his car is running good now for the first time since he's bought it!! Although he had a boat load of other problems before this.