Swapping 4 wire to 2 wire IAC

soul_sword34 · Post by **soul_sword34** » Sat Jan 26, 2008 11:39 pm

Just heard it's easier for the MS2 to control the 2001 style IAC motors than the 95-2000 4 wire stepper. If this is true how hard is it to swap the two wire for the 4 wire? In other words anyone work out the stepper idle issue?

Kevin_GP · Post by **Kevin_GP** » Sat Jan 26, 2008 11:55 pm

The 2 wire style works for both MS1 and MS2, the stepper does not work on MS1 and sort of works on MS2 (according to neons.org not many people have gotten theres to work right). You might as well just get a 2 wire, it will make things easier with either MS1 or MS2.

soul_sword34 · Post by **soul_sword34** » Sun Jan 27, 2008 12:15 am

I figured the 2 wire would be the way to go, my question now is how do I wire that in with my 4 wire and maintain factory idle while I build my megasquirt? Doing my intake first with the MPX 60mm.

Kevin_GP · Post by **Kevin_GP** » Sun Jan 27, 2008 1:26 pm

soul_sword34 wrote:I figured the 2 wire would be the way to go, my question now is how do I wire that in with my 4 wire and maintain factory idle while I build my megasquirt? Doing my intake first with the MPX 60mm.

Not sure, but to be honest when you are hooking up MS for the first time idle control is something you should work on once you get the car running (ie one thing at a time). I would just keep using the 4 wire till you get MS working, then switch over to the 2 wire. I have the settings for the 2 wire from turbodudey and it works great for me (stock TB)

Post by **occasional demons** » Sun Jan 27, 2008 1:40 pm

Doesn't MPX sell an adapter th use the 2000 IAC on the TB? That is what you will need till you ween the factory PCM of it's use. At least from what I understand, you want to run the TB and intake before you go MS? If that's what you want then it's the adapter or do the intake/TB/MS at the same time.

Scoll to the bottom....
http://www.modernperformance.com/produc ... ts_id=1346

Edit: never mind wasnt paying attention to the pic in #1 post... but you will need to go that route as there isn't any way for the 2000 PCM to drive the solenoid style AIC. You could use the newer AIC and shim it open with paper till you get the idle you want till you go MS, ( I did this when mine failed till I got a replacement [it is sping loaded]) but there will still be small driveability issues as there is no way to adjust for loads, and I'm sure there will be a CEL for the IAC. Not the best solution to keep from spending $25 on an adapter you won't need later, but it will work.

soul_sword34 · Post by **soul_sword34** » Sun Jan 27, 2008 6:29 pm

occasional demons wrote:Doesn't MPX sell an adapter th use the 2000 IAC on the TB? That is what you will need till you ween the factory PCM of it's use. At least from what I understand, you want to run the TB and intake before you go MS? If that's what you want then it's the adapter or do the intake/TB/MS at the same time.

Scoll to the bottom....
http://www.modernperformance.com/produc ... ts_id=1346

Edit: never mind wasnt paying attention to the pic in #1 post... but you will need to go that route as there isn't any way for the 2000 PCM to drive the solenoid style AIC. You could use the newer AIC and shim it open with paper till you get the idle you want till you go MS, ( I did this when mine failed till I got a replacement [it is sping loaded]) but there will still be small driveability issues as there is no way to adjust for loads, and I'm sure there will be a CEL for the IAC. Not the best solution to keep from spending $25 on an adapter you won't need later, but it will work.

Copy that. So I guess I'll get my intake/exhaust done first. Get the MPX 60mm with the 2000 IAC. Go MS then order the 2001 IAC and adapter. Let the MS have control of it. I'll get a CEL but I don't give a rats behind about CEL. I think this will work. Comments?

Post by **occasional demons** » Mon Jan 28, 2008 12:23 am

You need the adapter for the 2000 IAC, the TB is made for the 2001-up IAC. Like I said you will be buying an adapter that you won't need when you go MS, unless you keep it for back up if you need to use the factory PCM for some reason.

soul_sword34 · Post by **soul_sword34** » Mon Jan 28, 2008 1:10 am

occasional demons wrote:You need the adapter for the 2000 IAC, the TB is made for the 2001-up IAC. Like I said you will be buying an adapter that you won't need when you go MS, unless you keep it for back up if you need to use the factory PCM for some reason.

Good so I won't have to buy another adapter. Yeah it'd be a good idea to keep an adapter handy just incase my area starts emissions testing.

Jamie · Post by **Jamie** » Mon Jan 28, 2008 5:46 pm

Or even simpler if you have an old coil laying around do what... hell i cant think of the name right now... but wire it up somewhere hidden. idle evens out and everything is happy.

Yes MS2 can control the 4 wire idle but.. well ill just put it this way I have tried it, and i tested it, and I dont have it hooked up...

good luck tuning
J