Coil getting too hot causing a rough idle?

Do you guys suppose its possible for an MSD Blaster 2 coil to get too hot and cause the idle to get bad enough to where it feels like there is a cylinder or 2 down? Its mounted on a Performer RPM right in front of the carb, the motor can run up to 210 or so. The idle is great cold and very responsive but when its up to temp and coming to stop at a light it idles down really low and rough and will surge like its trying to pick up the dead cylinder.

no, coils are generally good or bad not in between

engage the carb power circuit & see what happens. sub in another coil & see what happens.

Coils can and do break down... but it can be a
LEAN carb... try a coil.. it made a day and night
difference on my junk
EDIT
I know I wasnt lean.. I was fouling out plugs

OK, I'll try a couple of things mentioned here. I have a stock replacement coil I can sub in and see what happens and then try some more carb tuning.

Back some years ago when I was a chrysler tech there was a service bulletin about coils. 76 and 77 cordobas and some other rear wheel drive cars would cut out going around corners. Turned out to be the coil shorting out from lack of oil, Loose cores inside the coil and or the coil heating up and cutting out. We replaced the coil and no problem afterwards.

Kenny B

All coils are not the same. There are high and low resistance coils. Some types of ignitions need the resistance, some don't. Using a ballast adds resistance...
This could explain an overly hot coil.

Good Luck

I am concerned about heat radiating from the engine causing the coil overheat. I also plan on moving to the inner fender and seeing if that changes anything.

If your using a coil that calls for a resister
and your not using a resister and running 12v
to it.. it will get HOT.. engine heat shouldnt
be a issue.. plenty of coils were mounted on the
intake.. now days they have 8 coils mounted on
the valve covers without issue... even on a HOT
heat soak the under hood temps get up to 300*..
and that was on a super hot day on top of black top
(117* that day in Death Valley)

Using a ballast resistor, Firecore dist, MSD Blaster 2 coil.

Since I moved my coil,ford starter relay and ign. box under the pass. side of the dash, everything last longer and the MSD 6200 box is well over 10 years old..........

Does that coil want a resistor ?

does your fuel have 10% ethanol ???

Sounds like the fuel is boiling.

I would upgrade to an E-coil and a GM HEI module.
The E-coil is much more efficient, can run on 12v and still doesn't get hot.

It is used with a resistor. Yes, the gas out here is ethanol 91 octane. It very well could be boiling. I have a thick base gasket to help with that issue but it may very well be getting close to boiling. I just keep putting off going to an electric pump.