I am running a Megasquirt v3 on my Transam with a GM TBI. The car starts fine, but will not idle. I pulled the AIC motor and it does not seem to work consistently. One time it shot the pin out. I got a new AIC and switch the coil leads, but it will not move. Is there a systematic way to test these AIC motors? Any help will greatly be appreciated.
John
Testing GM IAC
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
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johnTransam
- MegaSquirt Newbie
- Posts: 20
- Joined: Mon Mar 17, 2008 3:02 pm
IAC issue
I have been trying to get my IAC function to work. I have gone throught 2 IAC motor trying to understant this "simple" concept. I have a new IAC motor and to try and keep this simple I have set the start value at 160, the crank position to 0, and all of the temp table values to 0. When I turn the key on, the IAC is full retracted. The car start right up and within a minute I can get it to idle. It idles high but I expect that as the IAC is allowing maximun air in. Things are good for a while and then I hear a constant high pitch sound (which I assume is the IAC) and the car stalls out. When I turn off the car and pull the IAC motor, it is fully extended (no air flow). I have no idea why this is happening as it seems to be random. Any thoughts would be appreciate.
John
John
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Bernard Fife
- Master Squirter
- Posts: 475
- Joined: Thu Oct 29, 2009 12:54 pm
Re: Testing GM IAC
John,
Have you tried 'Always On' for the 'Idle Control/Algorithm'? You have to test it to make sure it can handle this, though. All of the stepper IAC test and troubleshooting tips are here: http://www.megamanual.com/ms2/IAC.htm#wiring
Lance.
Have you tried 'Always On' for the 'Idle Control/Algorithm'? You have to test it to make sure it can handle this, though. All of the stepper IAC test and troubleshooting tips are here: http://www.megamanual.com/ms2/IAC.htm#wiring
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw
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yellowlt1ta
- MegaSquirt Newbie
- Posts: 7
- Joined: Thu Dec 17, 2009 7:56 pm
Re: Testing GM IAC
I have a 93 trans am and my iac has the square plug. I had problems with my idle at first but I fixed it when i changed the settings, iac stepper always on and adjusted the idle steps. btw I dont know if your using tunerstudios.
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johnTransam
- MegaSquirt Newbie
- Posts: 20
- Joined: Mon Mar 17, 2008 3:02 pm
Re: Testing GM IAC
Thanks for the link. I have checked my wiring and it seems to be correct which is supported by the fact that the IAC fully retracts when the key is turned on. When I start the motor, it idles for about 30 seconds before you hear the IAC motor and the engine stall. If you pull the IAC, the pin is fully extended. Occasionally Megasquirt tries to recover before the engine can stall, but it seems to be a little to late. If you pull the IAC after this type of event, the IAC pin is fully retracted. I am using tunerstudio and I have the IAC motor set to be always on, but it does not help. I have MegaSquirt v3.0 MB, so I do not see any power resistors that I can jump. Any other ideas, or ways I can test my IAC would be appreciated.
John
John