EVO 8 stalling and idle issues
If it is the IAC, its fairly easy to take out and check. I noticed this on a friends Evo, where mine was fine. I just chalked the damage to his as being due to the Meth injection he was running..
Anyway, if you look at the valve, its basically a stepper motor with a cone that moves in and out into the seat of the idle circuit on the throttlebody. If you look at that cone, it should be held in place by three grooves, and there should be three "Teeth" that fit into the groove, when it gets worn, those teeth are gone and it can rotate. If it can rotate, it can't move in and out when the stepper motor rotates.
Its an easy enough thing to check.
Another possibility is the cam angle sensor is 180 degrees out of phase, since you said it wasn't as bad before it was replaced I would look there first.
The CAS sensor is what is used (In conjunction with the Crank sensor) to determine the ignition events and synchronize the ECU when you first crank it.. The fact that the Ignition has two coils, each paired as wasted spark (each coil fires two cylinders) the car will run, but will have odd issues that can be hard to track down.
The later posts are "airflow related" as different DV's open at different levels of engine vacuum, in doing that, it can drastically alter the airflow through the MAF sensor, which can also cause idle problems. Its important to be able to log the sensor data (RPM, fuel trims, IACV Position, Ignition, and MAF Frequency) as their dead giveaways to some issues.
Anyway, if you look at the valve, its basically a stepper motor with a cone that moves in and out into the seat of the idle circuit on the throttlebody. If you look at that cone, it should be held in place by three grooves, and there should be three "Teeth" that fit into the groove, when it gets worn, those teeth are gone and it can rotate. If it can rotate, it can't move in and out when the stepper motor rotates.
Its an easy enough thing to check.
Another possibility is the cam angle sensor is 180 degrees out of phase, since you said it wasn't as bad before it was replaced I would look there first.
The CAS sensor is what is used (In conjunction with the Crank sensor) to determine the ignition events and synchronize the ECU when you first crank it.. The fact that the Ignition has two coils, each paired as wasted spark (each coil fires two cylinders) the car will run, but will have odd issues that can be hard to track down.
The later posts are "airflow related" as different DV's open at different levels of engine vacuum, in doing that, it can drastically alter the airflow through the MAF sensor, which can also cause idle problems. Its important to be able to log the sensor data (RPM, fuel trims, IACV Position, Ignition, and MAF Frequency) as their dead giveaways to some issues.
Newbie
Joined: Jul 2006
Posts: 46
Likes: 0
From: shinjuku
hi there
thanks for that but it doesn't describe on how to access the IAC. My current thoughts would be to undo the two clamps connected to the throttle body and see how i go from there.
This is to help a good friend out with his Evo hence I will have to try it when he comes over again.
Anyway, thanks for helping . Cheers
thanks for that but it doesn't describe on how to access the IAC. My current thoughts would be to undo the two clamps connected to the throttle body and see how i go from there.
This is to help a good friend out with his Evo hence I will have to try it when he comes over again.
Anyway, thanks for helping . Cheers
Newbie
Joined: Apr 2009
Posts: 3
Likes: 0
From: Las Vegas
Does this part go by any other name. I found a part that looks similar to the diagram, it is called a throttle body. The dealership wanted to charge me 730 for parts and labor. I want to know if this is the same part with another name.
Any help would be greatly appreciated.
E
Any help would be greatly appreciated.
E
Newbie
Joined: Jul 2006
Posts: 46
Likes: 0
From: shinjuku
Try Japanparts.com They might have it there. If you were in Australia, I would recommend http://www.techsport.com.au/ - the best prices and service. Send an email to Jeff Beaumont at te33334@bigpond.net.au and see how much it is to get it mailed to you or something.
Gordo
Gordo
Newbie
Joined: Apr 2009
Posts: 3
Likes: 0
From: Las Vegas
Is the IAC Motor and the IAC Valve the same thing? I have found the valve in numerous places. Unfortunately Japanparts.com does not carry this. It looks simple to replace. Thanks for your help guys.
Last edited by Evolve16; Jan 12, 2010 at 06:07 PM.
this is awesome.. i been having issues to and have played wit my idle setting thousands of times and still stalls wen i come to a stop.. at first i thought it was my kelfords.. im gona check on the iac for sum reason i think its that.. i have an 03 too.. thanks guys
Newbie
Joined: Apr 2008
Posts: 40
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From: nj
I have a IX with only 30k on the clock and i have an idle that sits at 2500 and after it warms up it sits at 2000, and i have checked gakets hoses iac and maf, all seem fine. any input would be apriciated. also cars bone stock
Was this a random occurrence or were you messing with something?
Newbie
Joined: Apr 2008
Posts: 40
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From: nj