The IAC strategy on the Gen VI, has it's problems.
If the Idle speed is set too low, the IAC retracts, allowing more air in, in an effort to raise the idle speed, to the correct RPM.
Trouble is, is that the only limit is when the pintle fully retracts. Which means there's a 1/4" diameter air leak. I guess they're thinking is that the engine would stall long before that.
But, the real fly in the ointment is that during the IAC reset, if the pintle is far enough back, the program runs out of counts, and never is able to reset the IAC. So it's just a matter of doing enough resets/restarts to synch things up again.
And from key on to first crank you should allow a full 2 secs for the IAC to reset.
If the Idle speed is set too low, the IAC retracts, allowing more air in, in an effort to raise the idle speed, to the correct RPM.
Trouble is, is that the only limit is when the pintle fully retracts. Which means there's a 1/4" diameter air leak. I guess they're thinking is that the engine would stall long before that.
But, the real fly in the ointment is that during the IAC reset, if the pintle is far enough back, the program runs out of counts, and never is able to reset the IAC. So it's just a matter of doing enough resets/restarts to synch things up again.
And from key on to first crank you should allow a full 2 secs for the IAC to reset.
