I returned to Phoenix from the mountains today and when I got off the freeway and started out from the traffic light, the engine stumbled. It almost died at two more lights. I didn't think I would make it home. This happened
a few years ago but I can't remember if I ever found the cause. I filled up with gas before I left the mountains and I ran 70+ most of the way. Bad gas? I'm not sure but it felt like a backfire.

 

Could be bad gas.

 

Any codes?

High altitude mountain gas at low altitudes in hot weather could be vaporizing excessively.

 

First thing I'd think about is fuel system. Change the filter lately? Stick a fuel pressure gauge on there

 

I ran the truck on the freeway for about an hour and in traffic. I can't get it to stumble again. It was in rush hour traffic with the temp around 110 + degrees each time it happened. Oh well.

Thanks for the replies. JT