So my tachometer bounces like crazy when I am speeding! It goes like a trampoline from 100 to 120 km/h also when I am in stop position and pressing the gas pedal it starts bouncing.

 

That sounds normal if you're accelerating or at idle and hit the gas ...?

 

When in Idle too when i am accelerating the speed limiter comes on! and i am not that fast!

 

99% sure it's your throttle position sensor.

 

??? You're talking about km/r. That is a speedometer, not a tachometer. So please try to explain again what is happening!

 

When i am in stop position and step on my throttle some times my speedometer shows that i am accelerating although my jeep is not moving.
When i am on the move and reach to 60mph my needle starts bouncing. When i pass over 70 mph the needle starts bouncing and the speed limiter turns on. is like i turn off the engine while i drive!

 

Check your throttle position sensor.

 

Update! I changed my tps. Installed new battery and cables and ground cables to engine bay. Nothing changed! Any other ideas on how to fix it!

 

Could be the speedometer gear or drive gear. Teeth on one or the other or both could be damaged. speedometer is on the driver side of the transmission housing extension. on mine the drive gear was broken