My car has and still is running like a champ. Recently like 2 to 3 weeks ago the tach started jumping around, it was always inaccurate though, eventually i got a good deal on an autometer tach that I installed yesterday. This tach is reading the correct range however has the same symptom of jumping around and reading a little erraticly. The car does shudder just slightly somewhat often in drive with no gas.

I took of the cap and cleaned up the ICM which I recently replaced during my tune up around 2 months ago. It doesnt look like it did much the cleaning but i figured it couldn't be worse. I should note that my dizzy cap is just a little loose because the rear bolt broke, im going to get another bolt tomorrow to eliminate that. The wires came with the car in a box and appear to be in good shape and it wasn't doing this when I initially got the car running.

Im thinking if I can find a MSD blaster direct replacement at the right price ill throw that in with a msd cap and rotor. But i dont want to put any money into a 305. I have witnessed the car arcing also at one point, it was arcing to the coil, perhaps that fryed something? Thanks in advance, I tryed to describe everything to the best of my ability.