96 Silverado won 't start, but with a twist

Hi there, I hope that someone here can help. I have a 96 Silverado with a 5.7, auto., 4x4 with 95,000 miles that has some starting issues, and from what I've read on this forum, it's the only one I've seen with this problem. Plugs and wires and I believe the cap were changed about 15000 miles ago.

A couple of weeks ago it wouldn't start for me. It would turn over great, but no fire. Sometimes when I would let off the key (out of start but still in run) it would fire on one cylinder a couple of times. I tried for about 20 minutes before calling a tow truck and getting another ride home from work. The tow truck showed up about 1 1/2 hours later and started it up just fine. He still took it to the garage. They said that it appeared to be running a tad rich, but otherwise started fine. I picked it up on Friday and drove it home.

Monday, after sitting for the weekend, it would not start. The garage came out and looked at it, checked the fuel pressure (63 p.s.i.) and brought it back to the shop. Wouldn't start for them there either. The pushed it into the shop, fiddled with it, and then it started just fine, and has ever since. No trouble codes, nothing. They can't find anything wrong, and have asked around and noone else has even heard of this particular problem.

I'm looking for ideas as I don't trust this truck. Any help would be greatly appreciated.

Thanks in advance.

I would have the Injectors cleaned. I beleive the 96 has the TBI so there should only be 2 injectors.

Almost sounds like an ignition module acting up, maybe have it tested.