View Full Version : MSD 6AL testing

08-07-2003, 02:21 PM
i have the 6AL with a mallory promaster coil and mallory magnetic breakerless distributer on a sbc. the main power feed for the car found its way to the header and shorted. i replaced the wire, re-routing it, and at the same time ran new wires (taylor) and put plugs (ngk) in it. i have also put a new resistor in it. car ran fine (though not spectacular before the new wires) before the short and now has issues at about 3000-3500 (no tach). it runs real strong up to that, and if conditions are right (though i havent figured out what those conditions are exactly yet) and i can get it past about 3500 it runs real strong again. is there a way to test the box, or is there something else i should be looking for. i would really appreciate any help. this is my only transportation. thanks.

08-07-2003, 09:37 PM
If you are triggering the MSD through the Violet/Green wires then make sure that those two wires are not run near or along side any of the spark plug wires or the coil wire. You may be getting a false trigger through the magnetic pickup input which is causing the miss-fire. Also, make sure the green wire is twisted around the violet wire all the way from the pickup to the MSD box. The green wire acts as a shield for the violet magnetic positive wire. Try moving the wires to see if it makes a difference. Also, try looking for signs of arcing when it is dark. Start the engine and rev it up in the evening without any lights on and look for signs of a spark. If you see any that is a good place to start looking for a problem.

MSD Tech1