I am new to forum, and new to 3rd gen. I have an 89 RS TBI 305. The car will start great and run with no check engine light issues. I might drive for 150 mi. and turn off engine for a while, then sometimes it will fire right off and run 5 sec. and shut itself of just like I had turned off ignition. After cranking sevral times, I let it sit for about 3 to 5 min. it starts and runs great for another several miles, but the occurances are becoming more frequent. Last night it shut off while traveling 70 mph down the interstate. Before I could coast to a stop while trying to reach an exit, I restarted it and it ran fine and started after several stops the rest of the trip. Thanks in advance for any input on what I might look for.

 

I had a simliar issue with the vats vehicle anti theft in my 89 rs but I didn't have the off while driving, as for the vats your module might have gone bad but its hard to get to there is a way around it by getting the resistance of the chip in your key then buying a potentiometer (thats not spelled right) from radioshack that you can dial in the same resistance of you key and solder it in so your cpu reads the right resistance. Other than that the shutting off while driving I had an episode of this and there turned out to be a crack in the magnet of the pickup coil in the distributor....hope this helps I would look for the simplest causes first though plugs, wires, shorts stuff along that line. If it turns out to the vats or pick up pm me and I can tell you how to fix it fair warning though the vats will not work after words as the correct resistance will always be in effect...-dollar