Mallory Hyfire Ignition problem

Just put the Mallory Hyfire ignition on my 318 yesterday. Was on my way to work this morning when it just shuts off while driving down the road, after 40 minutes of running perfectly fine. Was able to crank it back over and get to work, but it kept doing the same thing, drive for a few minutes, then it would just shut off, no sputter, just off. Could crank it back up after about 30 seconds and cycling the key off and back on again. I've got the ballast resistor bypassed, so that might be the issue, followed the wiring diagram that was supplied with the box. Any help would be great.