msd ready to run

if its popping like backfiring through the carb you may have the distributor installed 180 degrees off...? Just a thought.

It sounds alot like the distributor is 180 out... BUT if you can hook constant hot power to it and it run fine, then there is another problem. Call msd, its the only way to save yourself some time and headache.

fwiw .... I just now pulled down an install sheet from the MSD site .... in the wiring diagram it clearly shows +12 VDC going to the positive side of the coil .... if you were using the OEM positive coil wire, it has a built-in ballast resistance in the ign circuit (that "pink" wire behind the dash at least in a '67) that limits the current through the coil during run (but is shunted by the starter relay during start) .... so the evidence you presented helps bolster the case that you should run a switched +12 VDC to the positive coil terminal .... switched meaning "on" for both start and run modes, but "off" for off and accessory positions of the ign switch ....

you'll have to hunt around the ign switch wiring to find a usable circuit wire that is "hot" for both start and run .... you could also add a bypass wire direct from the ign switch terminal where the "pink" wire terminates and run that wire parallel to the pink one, out through the firewall to the coil positive .... but keep the OEM push-on connector as that also supplies +12 VDC during start (from the starter realy bypass) ....

sorry if that is a tad confusing, but you sort of had the solution in hand already - just need to get it switched .... if you have a simple ballast resistor all you should need to do is jumper it ....also you may need to check the internal resistance of the coil as MSD may want a specific value that may be different from the coil you're using ....

good luck -- hope this helps ... you should be close !!

i agree with 67gtfb, it sounds like you are not getting enough power to the coil to run the ignition. if the timing was 180 out it would not run at all. another possibility is that the ignition switch is going bad. do you have other issues of an electrical nature? if not then just run a wire from the run side of the switch to the coil, that way you bypass the resistor wire in the system.

rbohm said:

i agree with 67gtfb, it sounds like you are not getting enough power to the coil to run the ignition. if the timing was 180 out it would not run at all. another possibility is that the ignition switch is going bad. do you have other issues of an electrical nature? if not then just run a wire from the run side of the switch to the coil, that way you bypass the resistor wire in the system.

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+1 from me. You two guys have it figured out.
Happy Motoring!