My 2002 Yukon XL with a 5.3 engine will die on me going down the road without any warning. It does not begin to hesitate or cut ot at all before this happens. Sometimes when I pull over it will still be running at about 300 - 400 RPM but when you step on the gas it does nothing but idle a little rougher. Some times it will be completely dead when I pull over. I can turn the ignition off and restart the vehicle sometimes on the first try and sometimes it takes several tries to get it restarted. Once it is going again it runs just fine, no loss of power, no hesitations nothing. It might run 50 miles or 1500 miles before it does this again. This is a flex fuel vehicle but I run nothing other than regular fuel in it. I have replaced the throttle position sensor and the crank sensor with no effect. No check engine light has ever come on and when put on a diagnostic tester no codes come up. I have already baffled many mechanics with this problem. Sure could use some more ideas. It just doen't act like a fuel pump going out although I have not ruled this out completely. I grew up working on cars along with all of my brothers and we can't figure this one out.

How many miles on it? How long have you owned it? When did it first start?

115,000 miles. I've ownedit for a year. Started doing this about 3 months ago, 2,000 miles ago.

FWIW, I had a very similar problem with my Chevy 3500 van. Kept dieing and getting towed in the middle of rush hour. Had the fuel pump replaced, a couple of times...(have to drop the damn gas tank to do it too) and finally found out the problem - there is a 3 foot long harness underneath the truck between the front and rear of the transmission that connects the tank sending unit and fuel pump to the main harness(it allows for disconnecting the harness for tranny removal). The connectors were f'd up inside somehow. Whenever it died and the fuel pump wouldn't run we jostled the connector and poof :it started pumping again! So I cut the f'in connector off (just had like 3 or 4wires anyway) and hot wired it with wire nuts and rubber tape. Never had another problem. What a PITA. Jeeze.