Pesky CIS Idle!!

[timjmcconnell at gmail.com (Tim McConnell)]

My car runs GREAT except for this weird varying idle that only happens 
sometimes.

Before you start - I have checked and fixed all vacuum leaks - there are no 
more. I have a freshly cleaned K&N Filter (not the cause) and have just 
removed the hot air return from the exhaust manifold. (also not the cause). 
I just cleaned out the airflow sensor bowl with a bunch of carb cleaner. Cam 
timing is perfect. Ignition timing is about 8 or 10 degrees advanced. The 
cap and rotor are new. The plugs are in nice shape (bosch platniums).

I checked the idle mixture (when hot) and had to lean it out just a tad. The 
idle is set at 950 RPMS. Aux air valve is fine, and the idle boost solenoid 
works good.

But - this is what happens - the idle will drop to like 650 - then the 
solenoid will open and it will go back. A second later - it goes back down 
and clicks again. It only does this sometimes. Sometimes the car starts 
doing it when I hit the brake pedal - sometimes not.

Anyone know about this kind of problem? The only thing I can think of is my 
fuel filter - I've never changed that. My fuel pump relay is great however. 
(I had that problem before)

--Timbo - early 1984 Scirocco 1.8 8v with CIS - No A/C and No PS and a 90A 
Alternator.

-- 
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