MSD Igniton Box shutdowns

[DonC]

Have recently been having intermittent shutdowns of the MSD 6AL (a new unit) after having the car shut off for a short time. Seems engine soak back is making box too hot and thanks to a Publix Supermarket being close by a 10# bag of ice got me running again. Mine is firewall mounted with rubber vibration isolators and about 1/2 " away from firewall panel. Is anyone else having similar problems with these boxes and if so any recommendations for a good reliable fix?

[first time builder]

I know you know the answer, move the box, We mounted ours inside the pass foot box. I know its a PIA but it works.

Kenny

[DonC]

With a Vintage A/C system already installed that one is going to be a miracle fit...I'll take another look at available space but my knee jerk tells me to move it forward in the engine bay or try a better box (my preference). This MSD unit is the second one to fail on me. Been considering a heat shield to help with the soak back after shutdown or maybe even a heat sink with small fan (not my favorite). When underway the system is fine, it's just the soak back that is making the unit inop till cooled.
BR
Don

[first time builder]

I have used the new street fire MSD box with no problems so far, they are less expensive and dont have all the features of the more expensive boxes but they seem to do the job. I always try to mount electronics inside the vehicle.
Kenny

[skullandbones]

You might consider checking the temps in your engine bay with a direct read thermometer and find a place like to the left and front of the engine (that could be the coolest point in the bay). It may be just a few degrees too much for the electronics and it may be cool enough to stop the heat soak process. I thought my engine bay was restrictive but the 33 is tiny!

Good luck,

WEK.

[Doutie]

Hi, I bought a very nice MKII from Dale G and about a month later I began having shutdown problems. It seemed to fail a 1/2 mile from the house each time I took it out. Each time I'd get out check all the wiring etc, and maybe about 10 minutes later it would fire off and then run great for an hour, until I parked it back in the garage. I have the stock distributer and finally just plugged the stock harness back on the coil and eliminated the MSD box. End of problem. I can also say the factory stuff lights the fuel very well to 6000 rpm without a miss. The red box looks cool but I don't need it. I'm telling you this storey just incase you have the problem again and can swing the ign. back to stock to get going. My harness out of the dist. was plugged onto the MSD harness and then the MSD feed the coil.
Just unplug the dist harness from the MSD harness and plug it back onto the coil as Ford designed it.

[tirod]

There are a lot of posts on the internet in many forums that support what Doutie wrote. Factory ignitions in the eighties achieved a high standard of operation because emissions controls required it Misfires are not tolerated in testing, a 50k minimum mileage warranty is standard.

For the additional cost, very few dyno reports show much in the way of street level horsepower gained from aftermarket ignition, and at rpms well above legal speeds or behavior. Since some makers moved manufacturing offshore in the last five years, the reputation of the units has declined considerably.

Factory parts aren't cool looking, but they do work - in many cases, for 250k miles. Race car parts trade reliability for an incremental increase in power at extreme levels of performance.

The OP well recognizes that the unit he has cannot heat soak and operate correctly. When it gets moved to a cooler location, the problem will be apparently solved. Sometimes the final choice isn't what we want and it takes time to accept it. In this case, disconnect the unit, wire the distributor direct, get a running car and have the MSD, too. Best of both worlds.

[robboy]

I've had no problems with mine but I only have about 500 miles on my 33. Mine is under the dash along with the Unisteer box. If you look on the other forum on the roadster side you'll find a wiring diagram that shows a workaround to get you going in case of a MSD failure. Also MSD's need to be grounded really well or they can be unreliable.