I have a 2002 silverado 5.3l vortec, I have had her since she was a baby (35k miles) She now has 170k, never had one problem until yesterday. Normally i change fuel filter pretty frequent but times have been hectic and i've managed to forget. So yesterday i was driving down a a mountain side and she started coughing and eventually died. I figured it was a clogged fuel filter. Towed it home, (After a 8 mile hike down the road). When started she would run and idle fine and as soon as you pressed gas she died or if you left it running for more than 15-20 seconds she'd die. Now, i changed the fuel filter, it was heavily clogged with the **** gas that is available nowadays... i couldn't even blow air through it. Now, she runs and will idle forever. And you can press the gas and she hesitates then coughs and almost dies or will die all together. I don't know if the nasty gas gunk got through the filter or what. But im having trouble figuring this out. I checked the fuel pressure regulator and no gas comes out when you pull the vacuum. But i did remove it a few minutes ago and im not sure if this is how its supposed to be but if you try to blow or suck through the **** it is very clogged feeling, only a very very small amount of air will pass through. Any suggestions?