Same night as when it cut-off with no warning. Basically it shuts down but the engines starts running rough, won't pull and acts like it isn't getting gas. I have to stop sometimes in the middle of the lane. When it shuts down this way, I have to wait 15020 minutes before it will start up again. If I try to start it earlier, it will turn over and fire but is very rough or the start seems to hang and it will not fire. Based on the differences in these two kinds of shut downs, I think it is an electrical or computer problem, not the fuel pump they want to replace and the fuel filter. These same two problems happened to me in June of this year and I took it to the shop. Nothing shows up on the computer as a problem. The only thing they did was replace the fuel filter. Someone will get hurt if this isn't corrected.

We bought the vehicle used 5 months ago and it ran absolutely beautifully until one day last month when the engine light came on. The engine started hesitating (like it was out of gas) so I drove it immediately to our local GM dealership. They called about every other day to say they didn't know what was wrong. Now, 4 weeks later there's still no solution and no actual diagnosis of the problem. They say the 1st & 7th cylinders weren't firing. Changed out many parts; replaced the head gasket, had the valves remachined and when they finally put it back together it didn't run any better than the day it arrived there (again, 4 weeks ago mind you). Said there was no compression one one side and his only option left was to replace the entire engine. Vehicle has only 58,000 miles. I cannot believe a GM engine can't make it past 58,000 miles. We've had no relief from the manufacturer either. JUST RIDICULOUS!!!