Bigfooter's Truck Has Big Problems? Any Suggestions?

My 2004 Chevrolet Colorado 4x4 that I got two months ago started going out on me on Christmas night in Green Swamp, threatening to abandon me to the Bigfoot there. Then the problem cleared up for about two weeks but started again and  has been plaguing me for the past three days. Yesterday, the engine stopped running six times while driving the truck. The first place I took it in the past several days ascertained that there was no vacuum in the tube of the fuel regulator ( I hope I have this right), and since he had no service bulletins, I should go to someone who did. The next place I took it told me that the engine wouldn't be running if the regulator wasn't working, i.e, the first place was wrong, and it couldn't use the computer unless I had a light on. I then went to an auto parts store that had a fleet of Colorados and found out that they weren't having any major problems with them. One worker told me that even if there wasn't a light showing for current problems, there was still information about historical problems available through computers. I also went to the library to google the engine symptoms. I found some nightmares about Colorados but didn't want to pay for answers at other sites.
I then took the truck back to the first place, told them what the second place had to say which the first place disagreed with. The mechanic then looked at the engine and said the vacuum could be better but it was not causing the engine to cut off. He proposed letting the engine run, putting a fuel system test on it, and driving  it himself to see if the engine would cut off. Of course, you know what happened: I waited it the TV room for five hours, and the engine did not cut off. At that point, the mechanic explained that though the most likely problem was a fuel pump, you didn't casually throw a new one on since that's a $500 to $800 job. I agreed wholeheartedly. He said if the engine failed again, I should hit the gas tank with a rubbler mallet, and if that started the fuel pump, it was a sure sign that was the problem. He showed me where to hit. I left the service center and bought a rubber mallet. I also told the mechanic that twice in trying to restart the engine, it began bucking and rattling so much I thought an engine part was going to fly off. He said that was an indication of a fuel pump problem.
  If anyone has a perspective to what is going on - and off- I'd greatly appreciate your comments. I want to get back to looking for Bigfoot. Peter Nickerson 352-359-0850  There's a comments section on my blog or call me. Thanks a lot.