when i try to turn the butterfly of the throttle body on my engine it is so hard i changed my throttle cable yesterday but nothing hapened it still so hard what can i do?? i have a Honda Legend V6 engine 1988 (my car is a rover sterling)

 

Remove the throttle body, disassemble it, clean it, sand/polish the shafts and bushings, grease the shafts and bushings, clean the inside (where the air flows), clean the throttle plate, and then reassemble.

 

can i do it my self or i need a mechanic

 

you don't even need to remove the throttle body, just remove the intake pipe, have someone hold the throttle down in the car and sand out the bore a little until it stops sticking. you may need to turn your idle screw down a little afterward since you'll likely experience a bit more idle air flow around the plate.

 

bad idea, you'll get metal dust sucked into the motor.

take the throttlebody off to do it

 

or vacuum it out. a fraction of a milligram of carbon and aluminum particles is fully negligible.