I have a 94 camaro Z28 it has a 4l60e auto trans and 180000 miles on it, i am rebuilding the motor to a 383 stroker after i figure this problem out[:@]. When i bought the car it reved to about 6300 RPM without a problem. now when it hits 5000 rpm it feels like the motor hits a brick wall. it will not rev out and because of this it wont shift. i recently put an opti-spark unit in as well as a new fuel pump and filter trying to weed out this problem. i dont know what to think anymore. anything helps please i am out of ideas. Thanks Dogan28.

 

Possibly due to old age. Could be the fuel pump or pressure regulator are sick, the cat may be partially clogged, or the intake getting choked up.

 

i cleaned out the mas airflow sencer and throttle bodie i recently was in the exhaust and it looked okay the injectors were checked and have good flow do you think it could be something internal. do you think i should just rebuild the motor and hopefully the problem goes away. thank you Dogan28

 

Is the SES lite coming on?? As the pump is new, it may be a good idea to check the pressure regulator. Use a pressure gauge on the fuel rail & see what the fuel pressure is when yu get to 5000 RPM under load. Due to the mileage you may still want to look at the catalist, as they clog up and choke up the engine at high RPM. Also before going too far, verify that the tach is reading correctly. Have you done any changes to the PCM parameters??

 

What did you clean the mass air sensor with? Cleaning them with solvents erodes the coating on them rendering them pretty much junk. By solvents I mean anything that is petrolium based.

 

what do you mean by pcm parameters. the SES light is on. and the solvent i usedwas not patrolium based. the guy i bought the car from chiped it and used one of those power programers like the hypertech. your supposed to take the hypertech out before you read the codes because it makes them all pop up. i dont have one so i cant take it out. when the catalyst is bad does it just clog up and you can clean it or do you have to buy a new one? thank you Dogan28[&:]

 

First of all get the car scanned & see what codes it is throwing. The Hypertech should not cause any extra codes to be set, so I belive the light is indicating some problem that you need to address. If the PCM has been reprogrammed, take the car to a dealer and get the PCM reflashed back to stock.