I have a 1989 Mazda MPV mini-van with 206,000 miles on it. It ran fine until recently when the idle went from about 800 rpm to 1500-2200 rpm. Sometimes it idles up and down between 1900 and 2200 rpm when in park. Any ideas? It also seems to not break like before. It is getting harder to stop. I don't know if this is because of the higher idle or if the master cylinder or power booster is going bad. Any help would be appreciated

 

Suspect a possible brake booster diaphram ruptured. This would not only create a high idle speed due to a vacuum leak but also limited vacuum assist in the brake system. Does the brake pedal feel much harder to apply then before?

 

Hi, i am having the same problem with my 2002MPV. already change the booster and master cylinder, checked and cleaned all brakes but still having the same problem. What I notice is
brakes are better on high rpm. I would appreciate any suggestions regarding this problem,
thanks.

 

I am having this same problem. High idle, and difficulty braking to a stop. How difficult is it to check the brake booster? Could I diagnose this myself? And will I cause further damage if I drive the car home until I can get it worked on or get a part? I can do some small jobs myself, but is brake booster a big job?