Subject: 3 ed coil no fire
Question:

1994 mitsubishi 3000gt vr4 v6. I am having a ignition problem only two coils are firing and the third is dead. The coils check out. I have changed the Power transistor unit. but still no spark from the third coil. I heard that it maybe the crank angle sensor or the ecu. What do you think 

Answer: Jai,
If your crank angle sensor was at fault, typically your check engine light would come on and your car wouldn't start. I would have your ECU inspected. You can read this article for further information:
http://90gsx.com/eclipse/cap/caps.htm

If your ECU is malfunctioning, you can have all sorts of strange problems. Have that inspected first before spending money on changing out any sensors.
Good luck!