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View Full Version : MISS IN IGN.


681 S/C
08-08-2003, 01:44 PM
I run a 7al-2 box with a crank trigger. I have a miss around 6,000 rpm, then it will go away. I have changed the 7al, wires, cap, rotor. After I ran new dist. and trigger wires, It went away for 12 pases. I grounded the - side of my coil to cyl. head. Worked good for 3 pases, then came back. I run a 2 step and rpm switch. The car worked great for 2 1/2 years ????
The shifter used to work off of the comand center. Is it possible the rpm switch is causing it?? 2-step??? Their the only things that have'nt been replaced. When I run a msd tester on it, says ok??? It ran good for 3 months prior to this. I have checked and re checked everything???? help

msdtech1
08-08-2003, 02:42 PM
If you are running a electric solenoid for your shifter then you may want to try putting a diode across the solenoid leads with the band facing toward the wire coming from your MSD device. This will protect the MSD from the kickback voltage that is generated when the solenoid is deactivated. Also, check where the magnetic pickup wires are routed. Make sure they are away from all the spark plug wires and the coil wire.

MSD Tech1

681 S/C
08-18-2003, 12:01 PM
I RAN NEW SHIELDED WIRE TO CRANK TRIGGER. DISCONECTED RPM SWITCH. STILL HAD MISS. CHANGED MAG PICKUP, IT'S FIXED. IT OHMS AT 82. WHAT'S THE DEAL? :(

msdtech1
08-18-2003, 04:45 PM
The pickup may have an intermittant break in the internal winding that may be causing the problem. You can try testing the pickup yourself by securely attaching the ohm meter leads to the two pickup wires and then wiggle/move the two mag pickup wires to see if you get a change in the ohm meter reading. Also try tapping on the pickup to simulate vibration and see if the reading changes. If you don't find anything send it in with a detailed note and we will do some additional testing on it.

MSD Tech1

681 S/C
10-06-2003, 10:28 AM
I TESTED THE PICKUP AS YOU SUGESTED, AND FOUND IT WOULD GO OPEN IF WIRES WERE MOVED AROUND. I SENT IT TO YOU FOR REPAIR. IT CAME BACK THE SAME. R.O. #114292 (SERGIO). SAYS GOOD UNIT ON INV. NOT TRUE!! I WOULD SAY THANKS BUT I DON'T KNOW WHAT IT WOULD BE FOR.

681 S/C
10-06-2003, 10:30 AM
I TESTED THE PICKUP AS YOU SUGESTED, AND FOUND IT WOULD GO OPEN IF WIRES WERE MOVED AROUND. I SENT IT TO YOU FOR REPAIR. IT CAME BACK THE SAME. R.O. #114292 (SERGIO). SAYS GOOD UNIT ON INV. NOT TRUE!! I WOULD SAY THANKS BUT I DON'T KNOW WHAT IT WOULD BE FOR.
ENGINE RUNS GREAT WITH NEW PICKUP. ONLY COST ME ABOUT $600 TO FIND THE PROBLEM.

msdtech1
10-07-2003, 10:22 PM
Obviously we did not find the open in the wire to the pickup. Either the wires where not moved enough or we just flat missed it. I have sent you an private message requesting that you return it to my attention so that I can replace the pickup for you.

MSD Tech1

681 S/C
10-08-2003, 01:59 PM
THANKS, IT'S ON IT'S WAY.

msdtech1
10-08-2003, 10:17 PM
I will keep an eye open for it.

Thanks,

MSD Tech1