Posted by Cliff Robb on August 26, 1998 at 12:42:17:
In Reply to: Re: rough idle... posted by Chandler Ogden on August 25, 1998 at 21:52:35:
The fact that the car runs good when cold makes me suspect the Aux. Air Valve. It's the one mounted to the valve cover. The solenoid you mentioned is the A/C compensator air valve. It sould only function when the A/C compressor is on. If your idle is not affected by the A/C, then this part should be o.k. Get a new air valve from Paul @ Maximillian. I have one being sent to me as I write this. Just tell him it's the same part that Cliff from CA. just ordered.
-Cliff
: Thanks for the input, Walt! Since I posted last night, I have been tinkering (strike that, obsessing) with the problem....I am leaning towards a vacuum leak problem. Trying to match the Haynes manual up with the actual pieces of the emissions system is a bit of a trick. As best as I can tell, I have 3 vacuum lines coming off my throttle body. One goes to the vacuum advance on the distributer (the temp switch on the thermostat housing has been bypassed), one goes to the charcoal canister, and a large one splits. One branch goes through the additional air valve to the cold start injector and the other branch goes through a solenoid between the throttle body and intake manifold (vacuum limiter?) I know I have a leak around the line to the charcoal canister....The "barbed" fitting that the rubber line fits over has been boogered with pliers, and I was able to remove it with my fingers (Is that supposed to be press fit in? I didn't see threads and it does not look sheared off..). I must have other leaks or problems, because when I plugged the hole in the throttle body, there was no improvement.
: When I first start it cold, it runs smooth (little to no missing). As the temp switch makes, the idle drops back and it misses almost to the point of stalling (4-500 rpm when stopped in gear). It seems to idle at about 800 when it is hot, but it still misses. I tried Peter's tip on pumping the brake pedal, and the rpm would drop off more when I did that.
: Does anyone know the symptoms of a failure in any of the emissions components (the solenoid or aux air valve). I have a feeling that the previous owner/mechanic has messed with the emissions system, so I would also appreciate it if anyone can confirm that I am not necessarily missing too many components....
: I figure I will try replacing a bunch of the rubber tubing, and then maybe resort to a tune-up by a mechanic with an O2 analyzer....
: Any other suggestions?
: Chandler