I have recently bought an 85 k5 blazer, starts great when cold, but after its warm it starts missing then dies. It back fires through the carb when you step on the gas before it dies. Then it is very hard to start again, you have to floor it and it sputters back fires but does start. All emisions have been removed, no EGR ect. I have replaced the wires, plugs, cap and rotor as well as the coil. Someone said the choke was sticking, so I wired the choke open. I have replaced the fuel filter and checked the timing (4 degrees BTDC) as well as the vacuum lines. It has an Edelbrock manifold and Quadrajet carb. Ran great for the first 3 weeks without an issue, it just started doing this. Any ideas?