Cobra cutting out

[patrickt]

Originally Posted by rodneym

What do you mean 'removed the rev limiter'? ... Doesn't that control the coil when to spark or is it only the limiter?

He means pull the chip out of the side of the MSD unit -- that chip is the "rev limiter" and interrupts the spark at a given RPM. And yes, the MSD unit controls when the coil's field collapses to cause the spark at the plug. FWIW, the way I tackle intermittent electrical problems (assuming that's what you've got) is to hook up different colored test lights to each part of the equation and have the lights literally right in front of me (taped to the dash, sticking out from the hood, it doesn't matter). When the problem occurs, look down and see what light(s) are not working and that will give you a clue. I just did that recently for a faulty ignition switch in my Cobra that was giving me intermittent no crank situations, and seconds later, cranked up perfectly. Before hooking up my test lights, I was sure it was the solenoid (wrong), battery (wrong), starter (wrong) ... and it proved to be the ignition switch. When the car wouldn't crank the light feeding the ignition switch was on and the light feeding the solenoid from the switch was off. Jiggling the switch just right could make the light blink on and off. By any chance do you have your coil mounted horizontally? If so it needs to be the "Hi-Vibration" Coil, otherwise you can get air pockets over a winding that can cause intermittent faults. Unless you know that little trick, it's a real pain to diagnose.