2000 Monte Carlo 3.4

when I go to start the car I have to put the gas pedal down to the floor. Once started the rps fluctuates from 8-14 while the pedal is still to the floor and backfires through the exhaust and sputters until the car die. It is getting plenty of gas.



replaced: Ignition control module, coil packs, spark plugs, tps sensor, fuel rail and injectors,

 

Try unplugging your MAF meter and see how it runs, if the engine runs after that your MAF is failing. Have you checked your fuel regulator too? Fuel filter?

 

Unplugged the maf and put on new wires still having problems.

 

First thought on my mind, check for vacuum leaks.

Also did anything change right before this condition started? Such as right after doing a repair or service?

 

I agree on the Vacuum leaks, that will kill the engine every time.

You might want to check for a larger Vac hose going into the firewall area on the driver side of the engine compartment, this just fell off on one of my vehicles and took a bit to find it.

You may also have a bad Catalectic Converter.
Also check your Air Filter to make sure it is new.

 

Did this happen before or after you started replacing stuff?

 

This problem existed before i started repairs.

 

i would do a smoke test to find potential vaccum leaks...maybe do a fuel pressure test to see if everything is holding pressure, mines was doing something like this twice, once it was because my fuel pressure regulator was going bad, and the second time it was because i forgot to put a hose back after a repair causing a big vac leak