i have an 85 z28 and its the h motor 305 v8 with the 5 speed... i am having a problem when i go for wot it wants to go now where... now i have replace the gas pump gas filter... and now i have replace the carb and the cap and rotor on it and it still does the same thing... if any one has any ideas as to y this keeps hapening and has done the same thing please let me know oh yeah i have also replaced the spark plugs... so any ideas as the next thing to change out please let me know... iam getting

 

What carb did you put on in place of the one originally on there when the problem started? What carb was on there?

Where is your timing set to?

 

i put the same type as what came off which is the q jet... it was reman... i got it from advance auto parts... and like i said i am haveing the same problem with this one as i did with the last one i just does not make sense... the other thing is the car runs fine untill i try to go to wot... i can go up in the rpms slowly and it is fine but as soon as i put the peddal to the floor it hits 3000 rpms and says that is as high as it wants to go with it wide open... i let off the gas pedal and it will go all the way up in the rpms pass 3000 and keep pulling ..... it does not make sense to me...

 

For some reason this topic looks familiar. You posted elsewhere, right?

A weak ignition will do what you're describing. Go for ignitions coil & module. Most likely that will clear it up.

You may also have a fuel line problem, such as a clogged tank pick-up sock or smashed line somewhere in the fuel path. A collapsing rubber line before the pump is another possibility.