78 Sc Rough Idle At Least
 

78 SC, SHAKES AT IDLE, SEEMS TO SMOOTH OUT SOME AT HIGHER RPMS. CAR SAT FOR 6 MONTHS, NOW HAS NEW PLUGS, PLAYED WITH MIXTURE, NO CHANGE. CAR STUDDERS OFF IDLE?? ANY HELP APPRECIATED. GARY

78 SC TARGA
83 SC TARGA

could be all sorts, plug fuel injectors, timing, etc. I would ensure all six cylinders are being fired...pull one plugwire at a time and see if you notice a difference. or you can pull all six fuel injectors and put them in a can and see if they spray when you lift on the sensor plate, fuel pump on "key turned buy not to start the starter.

There is alway a link on CIS troubleshooting on here.

I JUST REPLACED ALL PLUGS AND THEY ALL LOOKED SIMILAR. ILL TRY TO FIND BAD CYL BY PULLING PLUG WIRES. THANKS GARY

timing? loosen the 13mm nut and twist the distributor a few degrees in either direction. Does the rough idle improve?

Whoa! This is EXACTLY what happened to me. Get your hands off the CO mix and give the car a chance to shake the cobwebs! Baseline the car now and replace those parts that need replacing and ought to be replaced if you have no recent record of work. As an example, I replace my fuel filter twice a year.

Change the oil, air and gas filter, replace plugs (done), cap and rotor, and put in fresh gasoline with 20oz of Techron now. Set the timing and then take the car for a nice long drive of at least an hour at decent speed.

Screwing with mixture and whatnot is NOT what you ought to be doing at this point. That is akin to going directly to carb. jets and float levels as soon as you think something is wrong - the problem is always much more simple than that!

John
'78Targa

hmmmmm. My car did something similar to this, it just ran rough at idle and once warmed up, it ran perfectly. I believe the it was the fuel pump check valve, not sure if that helps you. However, it's a cheap fix. Kyle.

KYLE, HAD THAT PROBLEM LAST YEAR, CHECK VALVE IN "NEW" FUEL PUMP WAS NOT SEATING, NOW FIXED.
THANKS, GARY