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View Full Version : DLM Engine Misfire HELP


WV_Racin'
03-21-2022, 10:04 AM
Took car to test. Replaced coil, box, and swapped to big ford cap adapt kit. Car misses really bad at all rpm above idle while on track. Swapped to old coil, no change. Verified timing. Adjusted fuel pressure, jets, etc, no change.Really at a loss. Any ideas?
WV_Racin'
03-21-2022, 10:53 AM
Also, MSD sent an extension harness for the distributor. I noticed where it plugged into the main box harness, it went in green and came out purple and vice versa. Could this have been an issue? Once I corrected it, I reset timing and may seem to run a little better. Also had coil wire close to the distributor trigger wires. Anyone ever had interference issues with coil and dist wires?
cjsracing
03-21-2022, 01:08 PM
Also, MSD sent an extension harness for the distributor. I noticed where it plugged into the main box harness, it went in green and came out purple and vice versa. Could this have been an issue? Once I corrected it, I reset timing and may seem to run a little better. Also had coil wire close to the distributor trigger wires. Anyone ever had interference issues with coil and dist wires?

I believe it should be green to purple and vice versa on the MSD to distributor. There's an old thread on here, look up "Polarity" and you should find it. But going green to green and purple to purple advances the engine a lot and can ruin the engine. I did this once.
cjsracing
03-21-2022, 01:11 PM
http://www.4m.net/showthread.php?258069-BEWARE-msd-ignition&highlight=polarity
billetbirdcage
03-21-2022, 02:07 PM
if the pickup wires run parallel to the coil wire for any length it can mess up the timing. It's ok if it just crosses the pick up wires but better to have them separated to be sure.
WV_Racin'
03-21-2022, 02:54 PM
They were tied together with some other wiring/plumbing (rookie) lol.
billetbirdcage
03-22-2022, 02:26 PM
I believe it should be green to purple and vice versa on the MSD to distributor. There's an old thread on here, look up "Polarity" and you should find it. But going green to green and purple to purple advances the engine a lot and can ruin the engine. I did this once.

You probably know this and over looked it when you typed but worth repeating. Analog boxes are most retarded being correct and since most new boxes are digital they are most advanced.

Also worth repeating, I or anyone can be wrong from time to time so verify with another source that what is written is correct and hasn't changed with newer products.