i've got an '86 pickup that has a weird problem. every time you hit the brake the engine rpm will fluctuate up and down a lot but if you unplug the tail light sensor it doesn't do it anymore. any ideas on how to get no rpm fluctuation and taillights?

 

How in the heck did you even figure this out?

 

I had something like that happen .When I would hit the brakes the truck would like cut out . Idk If your having that prob,I replaced the brake booster and Fixed it .

 

i've been thinking about replacing the brake booster for a while because the brakes don't stop that well and i rebuilt all the brakes so the brakes aren't the problem.