I posted last week about my 94 LT1 shutting off on decel and accel. I got it scanned didn't show any thing, it quit as i pulled in my driveway, I tried to start it and broke the nose off my starter. I changed the opti. and fuel filter. I drove it this weekend it ran fine, but AC would not energize clutch and I could hear the relay close. I tried to start it Tues to get it scanned again, would not start. I changed the ECM and coil, it ran fine again. I went to lunch because the guy with scanner was busy, later as I left to go to his shop it ran about 1 min. and cut off the damn thing would not start again, no fire and now fuel guage was showing max. full with only 1/2 tank of gas. I apparently have a bad ground somewhere. I have checked the wires that ground at the stud at the ECM. I can hear the fuel pump run and have checked fuel pressure its ok. What have I missed? I can't very well get it scanned in my driveway. BTW I know the diff between crank and start.

 

Have you checked fuel pressure when the problem is occurring?

The resistance of the fuel sending unit is higher when the fuel is high. To me it sounds like the signal wire for the sending unit has a problem. It just so happens the fuel pump is on the same connector the fuel gage sending unit is on. It's a large 2 part connector located behind the rear seat. You can get to it easier if you remove the left rear tire. Chances are good the connector is bad and causing your fuel pump to drop out occasionally.