Hi all, I did quite a few searches but never locked on anything like I'm addressing here.

1987 GTA, 5.7 TPI stock, no mods, 118k on the ticker. Whenever the car is running in park, and I push the brake pedal down, the idle increases a bit. Is this normal, or do I have a small vac leak somewhere? Pedal is not spongy or hard, just feels normal except for the rpm increase. After pedal is fully depressed, idle goes back down to normal.

 

Check your Booster filter and connection going from your motor into the Brake diaphragm. Sometimes the rubber grommet that the filter goes into cracks or stretches and you will lose vacuum when the pedal is pressed. Also check your hose where it attaches to the valve cover.

Hope this helps, good luck!

 

Thank you, calirocz28, I will take a look at those items tomorrow and see what I find!

 

Yip, sounds like either a vacuum leak or the booster is failing. I think the car will rev slightly to "catch up" with the need for extra vacuum when something in the system is not working properly and you push the pedal.

 

It increases while the pedal is moving? Or while he's held still in mid stroke?

 

It actually increases WHILE I'm pressing down, then at full depression, it revs back down to normal.