IAC question... - ZR-1 Net Registry Forums

Ccmano · 08-17-2017

So the idle speed on the Z is a bit high by about 2-300 rpm. I've gone after potential vacuum leaks and I think I have addressed all of them. The IAC readings on my Tech1 are 0 at idle, indicating there is still an issue. In researching this I came accross Haibecks presentation on the issue. One of the items on his list is the IAC stepper motor. His test is to remove the motor, remove the o-ring and reinsert it into the throttle body. He says there should be a .020 gap between the TB and the motor body. Indicating that the pintle of the motor is seated against the TB, sealing it up properly.

http://www.zr1specialist.com/HAT%20W...5%20Engine.pdf

I checked the old one and found I had zero gap. So I picked up new one today from Summit. Even made sure the part numbers cross referenced. Darned if it doesn't do the exact same thing. No gap!

Has anyone run accross this? Does the 90' have a different IAC motor?

TIA
H

08-17-2017	#1
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,843	IAC question... So the idle speed on the Z is a bit high by about 2-300 rpm. I've gone after potential vacuum leaks and I think I have addressed all of them. The IAC readings on my Tech1 are 0 at idle, indicating there is still an issue. In researching this I came accross Haibecks presentation on the issue. One of the items on his list is the IAC stepper motor. His test is to remove the motor, remove the o-ring and reinsert it into the throttle body. He says there should be a .020 gap between the TB and the motor body. Indicating that the pintle of the motor is seated against the TB, sealing it up properly. http://www.zr1specialist.com/HAT%20W...5%20Engine.pdf I checked the old one and found I had zero gap. So I picked up new one today from Summit. Even made sure the part numbers cross referenced. Darned if it doesn't do the exact same thing. No gap! Has anyone run accross this? Does the 90' have a different IAC motor? TIA H