i have a 94 z-28 Lt1 camaro only thing done to the car that i know of is k&n cold air intake i drove the car one mornin got home and everything was fine and then went back out bout 5 hours later and started it up to leave and it starts shaking like crazy and smoking horribly its floodin itself out at idle or around idle but when u mat it to the floor it clears up and takes all the gas i replaced T.P.S coolant temp. sensor still didn't help so then i went and replaced the fuel pressure regulator and now the car won't start period it'll barely turn over like it has too much compression and then on the exhaust stroke it spins freely but when it almost starts the starter kicks in and locks it up HELP!?!?!?!

 

Kinda sounds like a cloged cat.

 

sounds like the fuel pump, but i dont know why it would be smoking? maybee a combination of the 2 clogged cat and fuel pump. if you need to do the fuel pump let me know i have a great way of doing it without dropping the rear or the tank.

 

Check the fuel pressure and operation of the fuel pressure regulator before even considering changing the fuel pump. If you think the car is flooding, crank it with the gas pedal to the floor. When cranked this way the computer shuts off the injectors to clear the flooded condition. Also check the 2 fuel injection fuses.
If the car flooded, then the plugs may be fuel fouled and won't fire right till they dry out. Check for spark at the ignition coil HT wire.

If as u stated the engine has trouble cranking at the compression stroke, there may be raw fuel sitting in the cyliders and it needs to be cleared out. You could also have one or more injectors staying in the open position. This can result from a bad injectors or grounded leads from computer to injectors. You can hook up NOID lites and see if they all flash during normal cranking, they won't flash with gas pedal floored while cranking.

Or you could be having ignition problems, which is a different story.