I was cruising along and the car stalled out for about 2-3 seconds and returned to normal. A mile or so later same thing happened again except there was a gun shot loud exhaust backfire with a smoke puff out the exhaust. The idle went back up to normal within a second or two to finally stall out and die on the highway. I never had to restart the car during any of these events. After it sit a few minutes it restarted but bogged down when giving it gas and died after 5 seconds never to restart. I did the basic tests after towing it home and it had no spark. I swapped out the module with a known working spare I have and no change. Both the module and coils are a year old and both are GM units. I had it towed to my personal mechanic because I was moving and didn't want to tow it a third time if I couldn't figure it out the issue. He replaced the crank sensor, module, cam sensor cap and tried a computer (it was a open box cardone unit). The car now has neither spark or injector pulse now. That was a month ago. I bought some stuff from Casper's to test the sensors today. I hooked up the sensor tool and the LED's lit up on the unit for module power, cam sensor, and the crank sensor (go figure right). I also plugged in the cam tool which did not light up telling me it's the issue. I loosened the bolt and tried to get the cam tool to light by rotating it and nothing. We came to the conclusion to replace the cam sensor itself which I did. I did TDC and rotated the sensor 25 degrees. The cam tool lit up. I snugged the bolt down. Car wouldn't start. It still has no spark or inj pulse. I swapped the prom chip out and nothing. I'm at a loss now. I don't understand how it has one of the other and then neither but the Casper's sensor tool says they are working. I don't have a known working computer to swap out. I really don't want to throw a $150 computer at it or any more money at it at this point until I can get something solid to go on. It's a stock engine 87 TR on E-85 with a TE-44. There is no engine codes present. I am a 20+ year veteran of turbo buick's but I'm just stumped on this one guys.