engine idle and mixture
 

Right now my 78 280 is idling at about 1500 and the mixture is WAY too rich. Its reading over 10% on the CO tester at the garage. The MAF sensor, ECU, and throttle valve switch has been changed. Adjusting the idle and mixture setscrews does absolutely nothing. Can anyone give some tips on trying to pinpoint this? Thanks.

hmm
 

hmmm... is the tps adjusted right?? also, the spring tensioner on the afm could be at a different adjustment than stock...

ok, sounds reasonable, how do i adjust the afm?

you take the plastic cover off the afm. under it is a what looks like a huge black gear. there is a screw and a piece of metal holding it on the side. hold the wheel, and loosen the screw, turn the when clockwise one tooth, tighten the screw back down. that gear looking thing in the afm is a potentimeter. a spring is behind it that closes the flapper. the tighter you turn the potentimeter (gear looking wheel) the leaner your car will run at idle. the looser (counter-clockwise) you turn the wheel the richer you run at idle. just hold the gear while loosening the screw because if you dont.. the gear will unwind itself and you will have a nice time re-adjusting it all.