I busted my IAC motors

[wayneandcathy]

I built the MS-II with v3 board and 2.9 code. I am running it in a 1984 Camaro with crossfire injection. I was setting the IAC steps trying to slow down the idle before I realized I had a pretty large vacuum leak. From the marks, it looked like I might have bottomed out the pintil in the throttle body seat. I had the open position up to 180. Or, maybe being 30 years old they just broke . The pintil would turn because the little plastic keeper was broken. I have two new valves and I have set the start up to 160, cranking at 110 in the IAC table I start at 180 degrees at 160 with equal steps to 40 at -40 degrees. all the other settings are default. I want to make sure I don't break the two new valves; their expensive. Also, I wired the IACs up according to the external wiring diagram . When I turn on the ignition the pintil retracts into the valve a lot, then extends part way back out. This seems right to me, but I noticed the wiring diagram under IAC and Fidle in the forum is different. Coil one is switched. Am I wrong?

[wayneandcathy]

Problem solved. I did have the stepper motors wired backwards. The diagram in this forum intro. is right for my application. When I tested the motor it first extended then retracted; just the opposite as it was supposed to. Also the IAC table is opposite to what I thought. so, I probably bottomed out the pintles in the TB seat and broke them. Wayne

[kjones6039]

I probably bottomed out the pintles in the TB seat and broke them. Wayne

I can not fathom, an IAC stepper motor generating enough torque to damage the pintle. After all, it is common for the pintle to make tight contact with it's seat. If the motor was capable of breaking itself, I would expect to see an unacceptable failure rate reported by many MS users, since stepper motors are very common.

Just my thoughts on the topic...........

Ken

[wayneandcathy]

I guess then they just succumbed to age, a problem I also have.