IAC reset without scan tool?

[Joe Hinds]

My dad has an 87 GN that is mostly stock and it has an issue with idling, and dying when you try to start off. Sometimes it will idle fine in the driveway, then it warms up (and I'm asuming is going into closed loop) it will cut off. I'm assuming this is probably due to the TPS/IAC, but I
'm open to suggestions. I have a digital voltmeter to set the TPS, but I have no idea to set the IAC without a scan tool. Is this possible? Thanks for any replies.

 

[pacecarta]

cant be set without a scantool capable of reading obd1
scanmaster , actron , autoxray, snapon, otc , or if you have a laptop ..directscan ,turbo logger or on the cheap winaldl

the easiest to use and highly reccommend tool for any turbo regal on stock ecm is the scanmaster

 

[Jerryl]

........I have a digital voltmeter to set the TPS, but I have no idea to set the IAC without a scan tool. Is this possible?

Try this .......
IAC Reset Procedure

 

[VadersV6]

Why would anyone need a scan tool to set the IAC? Dont stress over what people tell you. Theres a procedure for doing it, on practically all EFI engines from all manufacturers. That article should show 2 pins to jump on the ALDL. This sends voltage to the IAC, which makes the little linear stepper motor in there, push the pintle (cone thing) forward, and seal the bypass hole. Then disconnect the connector so it stays there. Turn the idle speed screw up a few turns so the engine can breathe without the IAC's help. With the motor warmed up, and after waiting at least 3 minutes or until it drops into closed loop, start slowly dropping the idle speed screw down just until the point the engine dies. Shut ignition off, plug the IAC back in, and there you have it. Worrying about actual counts of the stepper motor isnt really relevant. Each motor will have a different requirement (how far the pintle needs to be off the hole, for the engine to get enough air bypassed around the throttle blade to idle. Alot of people recommend a number in the teens, but this gives the computer alot less room to work with.

 

[pacecarta]

yeah whatever



to get the iac counts to around 20 so that you will have idle control for varying conditions you need a scan tool to see this and at the same time you are adjusting the throlttle stop plate you need to monitor the tps value

try this link not one posted back in the dark ages
Tuning (Idle Air Control) Adjustment