I've read a ton of crank no start posts and none are like mine. I have a 98 Tahoe with the 5.7. I drove it for about a year before out of nowhere it decided to not start. I did some research and checked the IDM, coil, fuel pressure, etc. it had spark and even if I put starter fluid down it's yap it still wouldn't fire off. The battery was starting to get drained so I put the trickle charger on it for a couple days. I went to start replacing ground wires and the thing fired right up. Drove it like that for over a month and then same thing. I went out and it wouldn't start. I tried to use my jumper pack but it didn't help and after cranking it would blink saying it was hooked up incorrectly... threw the trickle on it again and after two days I went out to push it out of the way of my jeep and again it fired right up. Seriously it turns over barely and fires off. I know I have fuel and spark and my air filter is new. Does the PCM need a certain voltage to work? Any ideas?