I bought this truck (1990 jimmy f/s 5.7ltr 700r4 auto 4x4) with a new fuel tank and pump. have been driving it to and from work for 3 weeks and no problem. then took it on the highway for a 160km scoot and the first town i entered i had to make a sudden stop and it stalled. started right away then quit again. pushed it to the curb and let cool down for an hr then it started and drove for another half hr then quit once again! waited for 1 hr and it started but didnt chance it and had it towed back home. All gauges read normal. running 91 octaine. Truck has headers and 3" duels and new rad. i am having a shop service the tranny and change the o/d shift switch.(goes into o/d at 50kph) anyone out there with any suggestions as to what i am dealing with would be great! new to here thank you.

 

it might sound dumb but check your oil level. u have a low oil sensor in the block that when it reads low oil it will kill the fuel pump/ injectors. i had the same thing happen to me

 

Could be your coolant temperature sensor or throttle positioning sensor. You getting any codes?.

 

I know it's a long shot .. take your fuel filter off carefully-- keeping it level - and drain it into a clear jar.
See any water?

PS: this isnt something I just dreamed up, it has happened to me and several others.. and your tank being new has nothing to do with it either.