hi, I am helping to look into a problem with my friend's 7. it is a 90 auto rx7. the car idles fine at about 700 rpm, and I step on the brake pedal, the idle seems to go lower, but still ok. and then after warms up, drive for a while, the car will stall if make a quick stop, like step on the brake hard. but if I am easy on the brake, slowly bring down the car to the stop sign, the car will still alive, but the rpm still go very low like 100 or 200 rpm, almost dies.

anything I can check? but the car runs fine at idle.

thanks

 

Vacuum leak most likely. CHeck the vacuum line going to the brake booster. Also, just to make sure, watch the volt gauge when all this happens, make sure it isnt dropping down as well. Could be a bad alternator or dead battery.

 

Check the BAC operation per the FSM (or Haynes) also...

 

thanks, hopefully, it is not a big issue.

 

how BAC is related to this problem? I am confused?

 

Pressing the brake pedal increases load on the engine, so the BAC tries to compensate. If it doesn't work, weird things happen...

But it's probably a combination of vacuum leaks AND a sticky/bad BAC.

 

i see, aaron, you are always a big helper, so do most of the forume members here.

will update after I clean the BAC this weekend.