View Full Version : Braking lowers idle?

01-06-2005, 11:50 PM
I just installed new spark plugs, plug wires, distributor cap and rotor today and I was out for a test drive. A possum jumped out in front of the car and I slammed in the brakes and clutch to stop and the car stalled. I stopped in time, but the car just stalled and I *know* the clutch was in all the way. Also, when I was sitting at idle, I noticed that when I push the brake in all the way, the idle lowers about 200RPM. Anyone have any fix or reason for this?

01-07-2005, 12:51 AM
sounds like you have some type of VAC leak. your brakes use Vac from the motor through the brake booster line.

01-07-2005, 12:52 AM
I'd say a brake booster vacuum leak.. yet that wouldn't cause idle to lower.. I take it you have the 5SFE MAP sensored right?

01-07-2005, 02:53 AM
its normal for a small drop in RPM as your engine relies on vacuum to run so you are taking away some of that vacuum for the brakes. sit at idle and push the brake pedal up,n,down up,n,down you will notice RPM's drop theres no fix its just how it is :D why it stalled is because the loss of vacuum an the rapid drop in throttle its normal :bigthumbu

01-07-2005, 05:43 AM
actually if you pump brakes fast you can make your idle rise.

01-07-2005, 09:09 AM
un plug your brakes. you dont need them

01-07-2005, 09:18 AM
Yeah, if you pump your brakes, it lifts up your idle. I have a simular problem atm, when i put my clutch in quickly and brake.i'm going to check for vacc leaks.

01-07-2005, 10:05 PM
Ah yeah where was my head at yesterday whata dick :noob:
Check the little valve between the booster and mannifold that shuld b lettn vacuum into the booster and not lettn it out.