IAC longevity problems

[MJones]

Is it critical, then, that the IAC never be allowed to reach the ends of 
its travel?  What happens to the IAC motor if the throttle blades are set 
such that the idle rpm can't come down into control range?  The IAC would 
go full closed.  Would the IAC motor be damaged by this?  Similarly, the 4D 
opens the IAC a fixed amount during each start sequence.  No matter where 
it was when last operated, it opens it further.  What happens to the motor 
if, when tuning/adjusting etc. you crank the engine over several times in 
succession but never start it.  The IAC goes open further each time until 
reaching the end of its travel.  Would this damage it?  If so, how does GM 
handle this scenario?

Beginning to sound to me like the closed throttle angle must be set such 
that the IAC does not go full closed, and that the IAC be disconnected 
during fiddling.  Any other ideas?

Mike Jones



Bruce Plecan wrote:



Sounds like the distance from the mounting "face" to the orfice is
too great allowing the pintle to be hyper extended, and too much of a load
for the stepper motor.    Might try to find out how to extend it,
installed, and record that lenght, and compare it to someone else's
That's all I can think of.
Cheers
Bruce