engine killing itself

Was the truck cold? I would bet it was the idle air controller.

no i just got done driving it home from a couple miles away and it has done this once before when i was slowing down for a turn and the lights started dimming along with it

It could be a fuel problem id check your fuel pressure first. But I had the same problem with my Camaro and it turned out it was the throttle position sensor. Took about a minute to replace and was only $20. Hope that helps.

Try pulling codes, none of the local parts stores will have the scanner for it since its obd 1 but there is a trick involving a paperclip and having you look it up is better than trying to explain it. Google GM obd 1 paperclip. If there is no codes then its a possibility its a fuel pressure issue. Sounds like there is a chance the pump is overheating then overloading or even the filter is in the first stages of getting clogged.

could possibly be an alternator problem its not charging properly all the time

how do you check the fuel pressure on these trucks

If its the 5.7 it's most likely an adapter between the fuel filter and the line for the fitting

your truck is still tbi injected if it is 95, there is no port to check fuel pressure on those. you have to remove the fuel filter, then a professional commercial duty fuel pressure tester kit comes with an adapter(3 way) that connects the two lines together with the filter removed and then the fuel pressure tester attaches to that 3 way fitting. fuel pressure on those setups in only 12psi

should state that is for 5.7 or 7.4 tbi injection, if your truck is a v6, then it has a vortec 4.3 and has a fuel pressure test fitting on top the intake, just follow the lines, and fuel pressure on that is 65psi

yea its a 5.7L TBI