What is the point of the retard system on my distributor? After disconnecting the vacuum advance line ( this line has no vacuum at idle) and disconnecting the retard line ( this line has full manifold vacuum at idle) and plugging the manifold vacuum line, then setting timing at 6 degrees BTDC and after plugging both lines back up, now at idle the timing is 2 degrees ATDC! What is the point??????????
My Pontiac had a thermostatic ported vacuum switch that would shut of the retard function when cold helping with warm up. At it was warm it dropped the timing back by letting the vacuum through to the retard port.
it was an attempt at emission reductions. by retarding the timing the cylinder pressures drop and nox emissions drop. over all it didnt work very effectively. it does work well for timing retarding under boost. you just leave the retard port open to atmospher pressure and run manifold to the advanced side and it will retard the timing with boost. so turbo up!
So I could just plug the port feeding the retard and then the vacuum advance will do it's part throttle thing and all will be ok?
If you plug it then it will have a hard time pulling the advance. Best to leave it open so it can breath better
Disconnecting the retard was one of the first things I did when I bought the 428CJ years ago... It also had the goofy vacuum switch that supposedly advanced timing if the engine were to over heat(thus increasing idle speed), tossed that as well leaving only the advance connected to ported vacuum on the carb...
