Car Starts then immediatly stops...help

Hi I'm new to the site, thought someone might be able to help me with am issue im having.
Today was the first day i tried to start it in a week and as soon as the engine starts it stops. It fires right up but then dies just as fast. If i keep the key in the all the way turned position it runs but as soon as i let go of the fully turned position it stops.
the ignition system was updated with an accel super coil. that is when the previous owner kinda deviated from stock wiring. the ballast resistor on the driver side firewall measures the proper resistence across terminals per the factory manual. The ballast resistor near the coil measures a little over 1 ohm across the two terminals. The right side of the coil's ballast resistor is getting full battery voltage, the other side has a short jumper wire that goes to the pos. side of the coil. It gets around 8 volts when the car is running. (i can kind of wedge the ignition switch in such a way that the car will run normally and that is how i've been doing these tests) So anyway it kinda seems like the ballast resistors are doing what they are supposed to. In light of the fact that the running voltages are ok, could a bad ignition switch be the cause of this problem? Although im leaning towards a problem in the harness, anyone have a problem like this before

sorry if this is lenghthy but the more information the better, thanks in advance