RPM revs at startup q45

[CJQ45]

For all you die hard Q fans,

Heres the deal:97 Q - 67k miles - cleaned the MAF, throttle body, replaced tension pulley for p/s pump, replaced fuel filter /air filter and a few light bulbs in the dash.

In the morning when I start the car - the RPM goes to about 1500 - normal. As the car warms up - it slowly drops but sometimes, the drop is sudden down to 1000 RPM and then quickly returns to 1200 RPM as the car is warming up. This happens only sometimes. Why? I cant figure it out.... it bothers me not to know why something is happening. Any ideas?

It also sounds like another pulley may be on its way out - I hope its a pulley. At start up in the morning - I hear a chirping sound - it goes away within a few seconds and then I hear a deep whinning sound which goes away after a minute or so. This is also occasional - most times the car is fine at start up in the morning.

ANy thoughts?

[PoorManQ45]

Try shifting into drive/reverse, let the RPMs drop down to below 1000. Then shift back into neutral. What does it idle at now?

Also, doesn't the IAC have something to do with Idle?

[Q45tech]

After crank rpm and progressive decline is controlled electronically and mechanically by a COMBINATION of the coolant temp [ecu to IAC] and the coolant temp [hox wax fast idle cam].

By now members should have memorized every page of the FSM and be able to guess probable rpm from coolant temp graph.

[elwesso]

Id try cleaning your IAC... Its possible that as it gets cold, the valve is more prone to sticking than when its warm...

Should be cleaned thoroughly every 60k anyway!

[CJQ45]

I think I should be promoted up from "hubcaps".... :-)

Anyway.. thanks for the advise... Its too cold in NY to do this now, I'll wait until the weather warms up a bit to clean the IAC. Does the gasket on the IAC need to be replaced or can I use the same one?

On a separate note -

does anyone know how much the stock rim on a 97 Q weigh?

Thanx

CJ

[DAEDALUS]

You might be able to reuse it if it doesn't tear on removal, but for the couple bucks it costs, it makes more sense to just buy it and have it on hand to finish the job faster.