View Full Version : Irratic Mechanical Advance
09-14-2003, 01:15 AM
I HAVE A FORD 460 WITH AN MSD BILLET DISTRIBUTER, MSD COIL, AND 6AL BOX. WHEN I TRY TO CHECK THE TOTAL TIMING, AFTER AROUND 3500 RPM THE TIMING MARK STARTS BOUNCING AROUND AND MAKES IT IMPOSSIBLE TO GET A READING. WHAT ALL COULD CAUSE THIS? THANKS
09-14-2003, 08:48 PM
You did not say what type of timing light you are using. That may be part of the problem so I would suggest trying a different timing light to see if it changes. Also make sure the cable from the timing light is not run along side the other spark plug wires. The light may be picking up the firing of the other cylinders. Make sure you are hooking the light to a cylinder spark plug wire and not the coil wire. What springs are you running on the MSD Distributor?
09-15-2003, 09:23 AM
I'm using a sunpro light, the timing light is connected to #1 spark plug wire, and the lead is not near any other wires. I set the dial to 32-34 degrees then run the rpm's up to get the total advance, then set the distributer to zero. As I rev the engine, I can see the mechanical advance working fine until I get up to a certain rpm then it starts bouncing back and forth to the point that I can't get a reading. I did set the timing on a friend's car and the light works fine so I ruled that out. I have a 6000 chip in the MSD. Could my chip be causing this?
09-15-2003, 10:02 PM
I don't believe the rpm module is what is causing the problem. The rpm where you said the problem is occuring at is right at the point where the MSD goes from multi-spark to single spark. Did the car that you set the timing on also have an MSD installed? If you have a freind that owns a fixed timing light (non-dialback type) then see if you can borrow it and recheck the timing at the same area that you are experiencing the problem.
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