Weird Idle

[drcorley]

my 86 944NA has developed a distrubing tendency to hang at 2000 rpm then
slowly drop down to idle.

if I am cruising then drop into neutral to coast up to a light, it will
drop down to 2000 and hang,once at the light I can go back into gear,
let the clutch out and pull the rpm down to about 1800 then it will drop
down to idle.

if I cruise to the light, slow down with clutch out, push in about 2000,
it will hang then slowly (like 10 seconds) drop to idle...

any ideas or suggestions ????

I have replaced the vacuum lines (the skinney ones, and will be replacing the "j" shaped boot that runs between the Flow sensor and throttle body in a couple of days.

[cyclemike]

Look for a vaccum leak else-where,try adjusting you idle, and check the TPS. Just a few things for starters.

[todd951]

I had the exact same problem a while back in my 951. I don't remember exactly what the cause was, but I think it was the auxiliary air valve (might also be referred to as the idle air valve or idle control valve).

[Pilot_951S]

I had the same issue last year. Faulty idle control valve. Also check the idle adjustment screw on the throttle body, somtimes these go missing mysteriously.