Hey guys need some help can't figure out y my 86 pickup 22re motor reeves up and down when I come to a light and apply brake any ideas? Only does it when at idle and brake is applied

 

check for vaccuum leaks. when you hit the brakes the booster demands vacuum from the motor to assist in braking. a leak in the line could cause a surge in the idle or if the diaphragm. Problem could also be in the booster as well if there is a crack in the booster or in the diaphragm it causes a leak in the system as well

 

yeah, most likely a booster problem. Mine did that once.

 

Ur idle should be at 750. Adjust it to do that

 

thanks guys great advice gonna check those things this weekend