My idle has gone all to s**t. 12A Streetport MSD ignition. Up till today car ran great steady idle very smooth even on our -30 days. Today on the way in to work the car started acting like it was running on one rotor. I checked all vaccum hoses electricals, changed plugs redid all connections on the MSD pulled and checked all plugs, adjusted throttle srew engine runs roughly at 1500 rpm when I advance the srew. Might be problem with second rotor leading plug - there isn't a noticeable change when I pull the wire but the coil is new and connections are OK. I noticed some black dust inside the dizzy which by the way is a NAPA. Could the cap and rotor be a problem - do others use only OEM ignition parts - any suggestions appreciated.

 

I've heard replacing those (dizzy cap and rotor) help with idling. Oh yea and before anyone else tells you to i'll go ahead and throw the "s" word.....SEARCH. not ragging, it's just what people say, I got it all the time.

 

Replace the plugs and see if that helps. Rotary plugs foul beyond rescue from time to time.

 

Hi and welcome to the board. Clean the indie of the cap. That black stuff may be a carbon trail causing it to spark to the wrong place. Also you could try either a new plug, or swap out that plug with the trailing plug to see if its the plug. You could do the same with the wire.