i have a 86' mazda rx-7. It's manual and no turbo. when im in gear and i hit the gas it jumps like it stalls. i spent $2,500 dollars trying to fix it and it still does that. Do you know whats wrong.

 

What have you done or had done to the car? What did you spend your money on?

 

I'm not real sure on what you are saying but my car used to do that after I pulled the engine and after looking to try to figure it our I saw that the MAF on the intake box was unplugged and that is why mine would iddle but not do anything above that without dying it is worth looking at to see

 

The AFM on a s4 must be completely level. If its slightly tilted or unplugged it will cause problems.

 

Mine is not level, and my car runs and starts fine.

 

when i hit the gas sometimes it wont even rev up. Oh my rpm gauge doesn't work how do you fix it.

 

That indicates that your trailing coils not functioning or firing. Either you plug wires are extremely bad, or your plugs are toasted, or the coil itself is bad. That could explain why the car runs like **** too.