:screwy: My 1990 Buick Regal Custom with a 3.1 liter automatic will start up at the slightest turn of the ignition key and runs terrific at high idle while it warms up for a full five minutes. But during the last minute of warmup, as the motor slowly calms down to almost a somewhat normal sounding idle, it simply shuts itself off as if someone turned the key off! After that, it refuses to start no matter how hard I try. I can crank the starter from now till domesday, but the engine cranks over and sounds as if it were completely out of gas, with not so much as even a single cylinder firing off. I've replaced all 6 spark plugs and the ignition control module (ICM) located under the 3 coil packs. What a pain that was to replace. But the problem still exists and I can't drive the car. All wiring and connecters under the hood appear to be in great shape. This is bizarre! I really wish cars were made as simple as they were back in the 60's and 70's. So many cars today are junked simply because of a bad sensor that nobody can figure out. I'm about to replace the brain box but first I need to know where it is located. Can someone help me with this or have any ideas that I've overlooked? Thanks

Welcome to AF, basics here, when it won't start do you have spark and fuel pressure?

How do I check for spark and fuel pressure?

You need a fuel pressure gage attached to the fuel rail port and a spark tester between the plug and wire. Due respect here, but it sounds like you may need some help with this.