Re: 1997 chevy 1500 gas tank
Pull the fuel line off up top and see if you can blow through it without too much resistance.
Fuel starvation causing a very weak mixture can sometimes produce symptoms similar to timing issues. If the line is ok, check the pump and the float chamber for any signs of muck.
Could be just coincidence of course that something else has cropped up - my Volvo is like that, goes for years without the slightest bit of trouble, and then two or three things crop up in a week. 'Sod's law', as they say.