I've been battling a smoking exhaust during decelertation

mode on my 75-280 since aquiring it last year.

Have rebuilt engine and have concluded that its not oil smoke

,at least not anymore. Cracked rings and head rebuild has eliminated

all oil consumption, and engine runs great.

However, still blowing smoke on decel mode, throttle closed conditions.

Thus, due to black soot, and eye burning odor, must be too rich.

#4 plug is more black fouled than others, so that injector may be stuck

open....and looking at AFM, the PO has apparently been fiddlin with the

idle bypass F/A mixture screw, cause when I opened it slightly CCW, the

decel smoke lessened.Has new engine temp sensor.

How much can I open it ( to add air ) during decel mode to compensate

till I get all injectors rebuilt ( durning winter downtime ) .

don't have a O2 meter. Have the info on adjusting the basic componants

of AFM, but they are silent on idle bypass , other than to say its factory

set.

I don't know if it will help with your problem Gene, but I finally found this link buried in the forums.... been looking for it for a while since I forgot to save it. :stupid:

http://www.72hours.net/~zcar/