Heres my problem. I have a 94 z28 (auto) that I have owned for about a month. It was doing great until today. I put the gas to the floor and the car just backfired and hesitated to shift. It really sounded like it was struggling. The engine felt like it was pulsing as it got to the high rpm's. The car does fine under normal throttle just driving in traffic though. Could this be an injector or a fuel pump problem? I really could use some help, so if you have any idea let me know.

 

that happened to me when i first got my Z, it was the fuel pump.

 

Replace the fuel filter, if still bad test the fuel pump and pressure regulator. See the sticky on top of this section for procedure. You really want to avoid changing the pump, unless necessary, as the job is quite involved.

 

Check to make sure that your plug wires and Opti-Spark distributor are not all oil covered!

 

I had the same problem with my car. What I did was a complete tune up and cleaned the fuel injectors. I think that should help, but if it still does it I think you have some kind of engine problem. On my Z28, I had to replace the valves, hopefully you do not need to do that. What could also help is if you check to see if your intake manifold is dirty, if it is, you’ve got problems. A dirty intake manifold can give you less horsepower and it make the car sputter. I hope I was of some help. Laterz