Unity Gain

So for about a week my 79 was idling very high at startup (3k) then would drop to 2k after warm up (still too high). Now from a cold start it does not idle high (warm up) and sits at roughly 400 constantly. Any ideas where I should start?

Thanks in advance.

jpitman2

Did you adjust or change anything in amongst these changes of idle?If not, I would suspect the throttle plate linkages are sticking or something. Does the idle come good when its warmed through? Idle is adjusted by the big straight slot screw head in FRONT of the spider body - anti clock to increase. Get it hot through , adjust idle to correct - 750 +/-50 IIRC. During warm up It could also be affected by a problem in the Aux air valve- remove hoses from both sides, shine a light through cold - should see through, close to fully open.
jp 83 Euro S CIS AT 56k