My 94 Z28 makes a horrible noise and and has no acceleration when i give it throttle past enough to get it moving. can anyone help. i've already replaced the plugs, wires, and the fuel filter.

 

[&:] well definately need more info from you. is the check engine light on, does it light with ignition on and engine off? where is the noise coming from, tailpipe, engine compartment, under car?? will it accelerate in park or neutral?? how does it idle, smooth or like crap, does it run ok just lacks power?? im thinking plugged cat at the moment but more info will tell kurt

 

I'm agreeing with t9ojetpilot, either plugged cat or possibly a leaky EGR valve. Does the car run ok once you get it moving?

 

Vacume leak?

 

well it idles really rough @ about 500 in gear and about 650-700 in park and neutral, the noise comes from the engine bay and the check engine light is off while running but is in with just ignition on and engine off.

 

fuel injectors

 

injectors or a vacuum leak somewhere

 

[&:] id be looking for a vacuum leak or a bad rubber boot on the intake system as either of these will cause the symptoms your describing