Replace IAC now idling high.

[Ruie]

So I just changed my idle control motor or whatever its called. Now it seems like I am idling around 1250-1500 when I was at 1000 on the dot.
What should I do?

 

[dsmcrzy]

Have you taken the car for a drive yet?

You have to get the car up to 50 mph and the iac will reset it's self and that should fix your problem.

 

[Ruie]

Okay, dont think I have gone over 40. Ill try that and let you know tomorrow.

 

[DSM1G90]

NO, the IAC NEEDS to be reset via the procedure listed in VFAQ, then you adjust the BISS screw to set idle speed.

 

[Ruie]

I see no way to reset the IAC on vfaq, just how to adjust the biss screw. Can you link me it? And for the biss screw since I dont have the scanner, I should do it up at advanced or somewhere with a scanner so I dont have to buy one?

 

[kchaazz]

I see no way to reset the IAC on vfaq, just how to adjust the biss screw. Can you link me it? And for the biss screw since I dont have the scanner, I should do it up at advanced or somewhere with a scanner so I dont have to buy one?

Setting the BISS screw via the VFAQ instruction IS resetting the IAC. Follow the VFAQ instructions for the 2G idle adjustment, though youll either have to have a friend who works at a shop allow you to use his diagnostic tool, or perhaps one of the parts stores will have the correct tool to hook to your car. Im going to do some searching and get back to you regarding the correct tool needed for this.

 

[romeen]

Setting the BISS screw IS resetting the IAC. When you ground the diagnostic plug via the VFAQ article, it allows you to use the diagnostic tool to hold the IAC to center itself, and the ECU relinquishes control of your idle, at which point you use the BISS to set your base idle the the factory target of 750- 800 RPMs, then unhook your grounds and you should be good to go. This is of course assuming you have no vaccum leaks anywhere and a fully functioning IAC motor and IAC driver in the ECU.

Do you know if there is a specific wire or pin at the OBD port that can be tapped and grounded if the diagnostic tool is not available?

OP, did you replace the o-ring?

 

[Ruie]

Yes, I put a new o-ring on and everything. When I drove it this morning ran fine seemed to idle fine. I can't find anyone around with the scanner, so I'm out on that one.

 

[kchaazz]

Do you know if there is a specific wire or pin at the OBD port that can be tapped and grounded if the diagnostic tool is not available?

OP, did you replace the o-ring?

Crap, sorry, shortly after posting that, I realized we were talking 2G cars, and I thought I edited my post to change to the 2G BISS adjustment method.
Correction: You hook a diagnostic tool to the port, then you have to use the tool to hold the IAC in the correct position while adjusting the BISS until your base idle is set.

 

[Leonthefaded]

Do you know if there is a specific wire or pin at the OBD port that can be tapped and grounded if the diagnostic tool is not available?

OP, did you replace the o-ring?

Thanks. This might be the reason my DSM is idling weird and random. I didnt replace my O-ring or follow the VFAQ. I did not reset the IAC properly either.

 

[romeen]

youll either have to have a friend who works at a shop allow you to use his diagnostic tool, or perhaps one of the parts stores will have the correct tool to hook to your car. Im going to do some searching and get back to you regarding the correct tool needed for this.

I can't find anyone around with the scanner, so I'm out on that one.

Yeah, none of the parts stores around here have scanners that can do that (the ones that they hook up). I vaguely recall a post regarding a $150 diagnostic tool from Harbor Freight (yeah, I know) that a member was really happy with. I think it was bryanwheat, but I'm not certain. Sorry Bryan if I'm mistaken. But I don't recall if it could ground the ISC.

Edit: Here's the post I was referring to. Although I'm still not sure if it can ground the ISC.

http://www.dsmtuners.com/forums/152886494-post2.html

 

[daren_p]

Technically I don't think you could call properly adjusting the BISS resetting the IAC, though I guess its sort of correct as the BISS, when properly used is adjusted to positions the IAC in its center of range travel.

After you swap out the IAC, you must reset the ECU (ie disconnect battery power). The ECU has no feedback from the IAC so it does not know its actual position. When the ECU's reset, its also resets the IAC back to a known position. If you simply replace the IAC & don't reset the ECU, it will no longer have proper control of the IAC.

After an ECU reset, you then need to adjust the BISS. This needs to be done with a scanner tool like the VFAQ states or can be done with ecmlink.

 

[romeen]

Regarding the Harbor Freight scanner I mentioned, it does NOT have the ability to ground the ISC.

 

[Ruie]

I took the battery out when I replaced it, so I would not have to pull off the tb. That has all been done, and now it seems to idle right except for when its cold. I wish I could find someone with the scanner everyones mentioning.