Thought I'd throw my 2 cents worth in... Stevebfl makes a good point about dynamically testing. Some coils will measure correctly with an ohmmeter, but will exhibit secondary breakdown - the coils will spark over inside due to a carbon trace or other path, and those failures can only be seen with an oscilloscope or by actual operating test. If it were myself doing the diagnosis, I'd swap out the coil before getting too deep in debt for a new one! Any old coil will do for a swap, and you should be able to determine if the coil is at fault or if it is the electronics that is causing the problem. Diagnosis by substitution is probably the best way to go in this case. You might find that you don't have a coil problem at all!