Low Idle Speed at Startup, Cold Engine

[Hoekie]

The motor idles at a very low speed on startup when cold. If I don't keep the revs up slightly with the throttle, the engine dies. As the motor warms up, it gets better and when hot, it will idle properly.

Any ideas what I can do to solve this?

[sammy]

You might clean you idle air control (IAC) valve. It's on the throttle body on the passenger side.

Please be careful and do not put any pressure on the end of it as you will break the spring.

[Hoekie]

Thanks Sammy, that is exactly where I looked this morning and you are 100% correct. :handshak:

When I dissembled it this morning I found is that the shaft with the little valve had come out of the electronics and the spring had lodged the taper tight into the hole in the plenum.

I managed to screw the little shaft back in but I don't know where it is supposed to sit exactly. I then put the IAC back on and the car now idle's, even from cold, and it is also not running as rich as it was.

Amazing when you solve the problem that everything suddenly fits.
As they say "hind sight is always the perfect science"

I will obviously purchase a new IAC but any recommendation on make? My problem is I'm in South Africa so it will have to be RockAuto or someone like that. :)

[sammy]

rock auto would be as good as anything .do you have a factory service manual , you know the one the size of a bible .?if not i would invest in one .they are worth their weight in gold . glad you found the problem . have a great weekend

[Hoekie]

Thanks

Yes I do have one got it with the car.
Have you maybe tried to dismantle one of them?
Also changed the fuel filter today and found the old one was installed the wrong way round!!! Dont know if it really matters but it does show direction of flow.
Im still new in playing with a ZR1 but we are getting there. Only have the car for a few months now

[sammy]

no i havent . get a new iac from rock auto .there will be a little adjustment you might have to make to it before you install it then there is a little procedure in the fsm . the first time you start the car with the new iac installed .. good catch on the fuel filter . i change them every 10k miles on both my zr1s .