95 Sonoma issues

[GM 4 Life]

Please help!! I bought a 95 sonoma X cab w/ 225,000 mi. It's OBD 1 & got the 4.3 TBI 4spd auto. Its all stock & looks to be all original. When I bought it it ran on what felt like 4 or 5 cylinders.I have never drove it like this.Now it will not start. I have replaced the radiator,fuel pump,fuel filter, dizzy, cap,rotor,plugs wires, coolant temp sensor,egr valve, rebuilt the TBI, replaced IAC valve, & main computer.I have verified all grounds & fuses. checked valve springs, pushrods, checked the timing chain for a jump. I removed the exhaust from the manifolds & ran it with no change.The motor looks super clean inside, no sludge in the heads etc. Its getting fire & fuel & still will not start. Even giving it a slight spray of staring fluid does nothing. It turns over strong but never hits. This truck was running before. It's a sweet original truck but I'm about to part her out cause I cannot figure it out & all the garages around here are just parts swappers & money burners. Thanks in advance.