97 GC Problems HELP!!

I have a 97 GC that does not want to run. I built a .030 5.9 for it 6 months ago, put it in and it has been running great till two weeks ago. It broke #1 ex. valve spring, so I replaced that one and ordered another set from Crower, replaced all 16 of them last week and did a leak down test on all cylinders to be sure it didn't burn a valve. Last saturday it started to run bad, like another valve spring had broke. I was on my way home, the braket for the power steering pump broke, it through the belt, broke 2 blades off the fan ( it's a 10 blade plastic fan from an explorer) ripped the trans cooler lines apart and put a slice in the lower hose. So I walked home (1/2 mile) got my Suburban and trailer and towed it home. I found a junk yard that was opened sunday and got a new bracket, and fan. Put it back together and it now has a miss. The Crank sensor is original (187,000) so I replaced that with no luck, I put new cap, rotor, wires, plugs on it with no luck. It will start then only stay running if i keep my foot on the gas. If you try giving it any gas it shakes and stumbles, and twice popped though the intake (like its lean or timimg is off) I am going to try a Cam sensor today to see if that could be the problem. I am getting a CEL I put my scanner on it and it will not communicate with my scanner (Genisys OTC). So I am thinking it may be time for an ECM all the fuses are good. Is there any way to check or test before shelling out $300 for a new one? The only things that have not been replaced are the TPS, MAP and Cam sensor. It has the Siemens 24# injectors (53030778). I don't want to start replacing parts if it is not going to fix the problem. I put a timing light on the plug wires and coil wire I was getting an intermitten spark loss on all of them, so I am thinking it is an ignition problem. The coil was new with the motor and ohm tested good hot and cold. This thing is driving me nuts and help would be appreiciated, thanks

Rob