Rough idle on 76-280s

8 Mar 2000

Within one week of a tuneup and state inspection, my 1976 280s developed a VERY rough idle. At times it is as if 2 of the 6 plugs are not firing. The idle is so rough that the engine almost dies. In the morning with the engine cold, it cranks first time and runs smooth for about a minute, then the roughness starts. At any speed other than idle engine seems to run fine.

My mechanic can not find the problem. Engine has 225k miles and is carburetored. Carb was rebuilt a few years ago. No change in oil usage or gas mileage. Wires were replaced about 8 months ago.

Any thoughts, suggestions or questions would be greatly appreciated.

Thanks
Stephen C. Stierstorfer
acje@flash.net