92 GT SHUTS OFF AT HWY SPEEDS

[WHT306]

Ok I have gone through many tests with the ele. system fp, fp relay, eec relay, maf, tps, tfi mod. every thing seems to be checking out but the car will run great one time and the next time it will try to fire but then kills out, or it will run a few minutes and die i had a spare fuel pump and relay put them in ran fine drove it about 30 min. shut it off cranked up fine drove about 35 min and shut down on the interstate at 70-80 mph, sat for 15 min trying to crank on and off cranked up and ran fine drove all the way home no issues. tried today and tries to fire but no. does anyone think this could be the ign. switch on the column since it supplies power to everything on the car to run?

any help would be great thanks.

 

[Notchbck93]

Ignition switch or coil negative wire that runs to the computer...I've seen them broken in the harness right around the firewall.

Check the leads that plug into the coil as well. Once in a while you'll get a TFI module that heats up and shuts off because the thermo grease behind it has dried out.