'79 Turbo Intermitant Starting

[Germaneighter]

I've posted a couple times earlier this month about this problem. Sometimes the car would not start or would die after running a few minutes. Did not seem to be temp related. I could wait ten minutes and it would fire right up or I could wait two days before it would start.

The CDI box was replaced with a Perma-Tune unit by PO.

I have verified the ground connections are OK. I got on the Perma-Tune site and performed the bench tests outlined in their trouble shooting guide. All checked OK.
The factory coil (transformer) looks a like some of the tar is starting to seep out from around the top cap. Perma-Tune said I could replace the factory coil with any quality conventional coil. I replaced the coil and the car has started everytime for about a week now.

I thought my problems were over until tonight. The car backfired pretty hard right at start-up then started running really rough. It has a steady mis-fire. It does not have any power. Like it is only hitting on four or five cylinders.

I called Perma-Tune for any suggestions. They were very willing to talk about the problem over the phone. They recommended that it might be the speed control. What is this? Is it Turbo only? (I'm new to turbo ownership.)

Any help would be appreciated.

DLG