1974 V6 rough idle after new coil installed?
Recently purchased a Mustang II 1974 V6 engine with dual carb. Engine idled nice and smooth until I had the starter coil replaced at the garage. Car went in idling fine and came back idling really rough, shaking and almost stalling. Drives fine but almost stalls at stop lights. Garage says they didn't do anything but replace the coil.
I replaced the plugs, cleaned the distributor cap and installed new rotor. My carb doesn't have an idle control solinoid. Checked the new coil connections and they are fine. Even put in the old coil and it still idled rough so I don't think it's the coil.
What could be the problem and how to fix without another big bill!
Thanks for any advice.