pros-cons with IACV removed?
Thread Starter
Bannisheded
iTrader: (33)
Joined: Jan 2009
Posts: 1,056
Total Cats: -3
From: San Jose, CA
Im having problems with my Idle air control valve.
i must have screwed up somewhere during my wire tuck and now it constantly has power even with the key in on position.
I can fix it but im to lazy now.
I plan to make a block off plate if i do decide to remove it.
What id like to know is how will my warm up idle and normal idle be effected?
i know a few here dont run it but is there anything special i will have to do as in change some setting in the warm up tune or anything of the sort?
Thanks
i must have screwed up somewhere during my wire tuck and now it constantly has power even with the key in on position.
I can fix it but im to lazy now.
I plan to make a block off plate if i do decide to remove it.
What id like to know is how will my warm up idle and normal idle be effected?
i know a few here dont run it but is there anything special i will have to do as in change some setting in the warm up tune or anything of the sort?
Thanks
Thread Starter
Bannisheded
iTrader: (33)
Joined: Jan 2009
Posts: 1,056
Total Cats: -3
From: San Jose, CA
The IACV has a signal wire and a power wire, i just spliced the IACV's power into a 12v source that also powers the ecu, CAS and injectors etc.. I found out that this is the correct power source for the iacv but for some reason its powered. like i said im to lazy to try and correct this.
Joined: Sep 2005
Posts: 34,403
Total Cats: 7,523
From: Chicago. (The less-murder part.)
I've been working all day. And frankly, I'm a tad confused by your description of the problem:
It's supposed to.
In the stock configuration, the white/red wire at the IACV has a constant +12 from the Main Relay any time the key is in RUN or START. This is the same circuit which powers the CAS, ECU, injectors, purge valve, fuel pump relay coil (via AFM switch), and probably a few other things which I've forgotten.
Then there's the blue/orange wire which runs to the ECU at pin 2W, where it is switched to ground through a transistor to energize the solenoid.
So, what exactly is the problem? If you're saying that it the valve is constantly energized, then you probably shorted the blue/orange wire to ground somewhere.
It's supposed to.
In the stock configuration, the white/red wire at the IACV has a constant +12 from the Main Relay any time the key is in RUN or START. This is the same circuit which powers the CAS, ECU, injectors, purge valve, fuel pump relay coil (via AFM switch), and probably a few other things which I've forgotten.
Then there's the blue/orange wire which runs to the ECU at pin 2W, where it is switched to ground through a transistor to energize the solenoid.
So, what exactly is the problem? If you're saying that it the valve is constantly energized, then you probably shorted the blue/orange wire to ground somewhere.
Thread Starter
Bannisheded
iTrader: (33)
Joined: Jan 2009
Posts: 1,056
Total Cats: -3
From: San Jose, CA
Yes when i plug it in, it activates the iacv instantly so i constantly hear it clicking, it scares me..
The blue/orange wire is wired directly to the yellow female ecu connector so there is no way it can be grounded.
OK. so before i posted that^^ i went to double check the wiring and its solid..no way the blue/orange wire can be grounded =(((
also pm'd you Joe
The blue/orange wire is wired directly to the yellow female ecu connector so there is no way it can be grounded.
OK. so before i posted that^^ i went to double check the wiring and its solid..no way the blue/orange wire can be grounded =(((
also pm'd you Joe
Yeah mine doesn't idle well when cold, but I either take off immediately or put my foot on on the throttle for a bit. I've had a carb'd 1953 Chevy pickup, 1985 Suzuki bike, and a Honda 400ex. They all required a little generous throttle application when cold, so this concept of having tricky electronics keeping my idle exactly the same when cold is really foreign to me. It's all dead weight if you ask me.
I just cut off some of the throttle body and welded the holes shut for this build. I'll let you know how it idles (Gonna do some timming advance on idle in AEM to compensate hopefully)
My valve is dead, and therefore my idle varies from like 1200-1800 once warmed up. The only time it idles at a "normal" rpm of 900-1000 is when I first start it. Kind of annoying, I'll replace the valve when I swap my new motor in. I grabbed one from a 50k mile motor which works perfectly when plugged into my harness. My current valve doesn’t even hum or click anymore...
mine runs fine with no IACV, its hesitant when its cold but, like Curly said...its like driving anything that is carb'd. My Dart is the same way. And it looks nicer too without the wires running to it. IMO of course
My IACV died partially open, so I just unplugged the electrics to it, backed out the idle screw a bit, and the car idles steady at 1000rpm. I also installed a PCV valve on the IACV intake so that when boost happens it seals up.
Thread Starter
Bannisheded
iTrader: (33)
Joined: Jan 2009
Posts: 1,056
Total Cats: -3
From: San Jose, CA
Problem solved thanks to MarcD coming over to help me!
After fixing other stupid issues with my new wiretucked harness we moved onto the IACV. Turns out it was working all along..sometimes. I wasnt getting a solid connection from the 12v to the MS so when the MS would power off, the MS wasnt keeping the IAC shut and but the IAC would still get a 12v signal which would trigger it to turn on and off constantly.
All this worry because of a loose 12v connection at the ecu..
I deserve a ciggarette now
After fixing other stupid issues with my new wiretucked harness we moved onto the IACV. Turns out it was working all along..sometimes. I wasnt getting a solid connection from the 12v to the MS so when the MS would power off, the MS wasnt keeping the IAC shut and but the IAC would still get a 12v signal which would trigger it to turn on and off constantly.
All this worry because of a loose 12v connection at the ecu..
I deserve a ciggarette now
Thread
Thread Starter
Forum
Replies
Last Post
EricJ
Suspension, Brakes, Drivetrain
7
Sep 11, 2021 11:10 PM
bigmackloud
Miata parts for sale/trade
19
Jan 8, 2021 11:24 AM
StratoBlue1109
Miata parts for sale/trade
21
Sep 30, 2018 01:09 PM
stoves
Suspension, Brakes, Drivetrain
5
Apr 21, 2016 03:00 PM
ThunderFox
Suspension, Brakes, Drivetrain
2
Sep 10, 2015 03:19 PM









