91 Chevy Silverado starting problems?

[OLD DRAGONS GUARDIAN]

I recently had a friend give me her husbands 91 Silverado 4x4 with the 5.7 liter Vortec engine that had been sitting for 2 years. This truck has 28,000 original miles on it and when I first brought it home it would start on the first crank. I drove it 2000 miles with no problems but now it takes 3 or 4 tries to get it to start. I wait for the fuel pump solenoid to click before cranking it and have to do this 3 to 4 times before it will start, and if I let it sit for half an hour or so I have to do the same thing again. I've had different people tell me that it's the fuel filter, the fuel pump, a check valve in the carb, or maybe it's in the electronic ignition system, so I have no idea where to start looking.

This truck looks like it just rolled off the showroom floor and I really don't want to make things worse so any help would be very much appreciated.

Thanks

 

[vip.auto]

After sitting for so long the fuel in the tank degrades severely, even after you added fresh gas the old fuel was still in the system and has likely collected in the fuel filter clogging it to the point that it is taking a while to get enough fuel through it to build enough fuel pressure at the injectors to run the engine.
There is a spring within the filter that will compress to allow a bypass condition should the filter element become so clogged as to be completely impassable which would give you exactly the symptoms you describe.
Replace or have the filter replaced, fill the tank and add a quality fuel system cleaner. Your GM dealer sells a Goodwrench version or use some from your auto parts store.
The filter has a service interval of 30,000 miles so changing it is needed anyway, and if I'm right and it is operating in bypass mode, you are getting unfiltered fuel at the injectors which can do nothing but harm so don't wait to long.
If that clears things up finish with a full tune up, regardless of miles those spark plugs have been in those heads WAY too long. Good luck.