1990 corvette engine races and takes off when brake pedal is depressed. Happen in drive and reverse. Getting scary.

how to test a brake booster

https://www.youtube.com/watch?v=ogXIHfrhXsQ

or
Run the engine for one or two minutes, and then stop it. Depress the brake pedal several times at normal foot pressure. If the pedal goes down further at the first time, but gradually rises after the second or third time, the brake booster is functioning properly.


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check the brake booster internal membrane /boot is ok

is its non return valve ok

Chevy Corvette 1990-1996 Factory Service Workshop Repair Manual

Chevy Corvette 1990 1996 Factory Service Workshop repair manual...

Covers:Chevy Corvette 1990-1996

This manual contains all the necessary instructions needed for any repair your vehicle may require from bumper to bumper.
Whether its routine maintenance, such as tune-ups and brake service, or more extensive repairs involving engine and transmission disassembly. This file provides the most reliable information to perform the job.

Accurate, clear and concise text, combined with illustrations, make it possible for anyone with even a bit of basic mechanical knowledge to safely and easily service and repair their vehicle.

Comprehensive diagrams, in depth illustrations, and all the manufacturers specifications and technical information you will need is included.

Section included:

Tune-up and routine maintenance
General Engine overhaul
Automatic Transmission
Transfert Case
Driveline
Brakes
Suspension and Steering
Body
Chassis Electrical

Format: PDF - Download
Years:1990 1991 1992 1993 1994 1995 1996
Compatibility:any windows (95-98-ME-XP-7-MAC-LINUX-IPAD-IPHONE-IPOD)

There is more to the throttle then just the pedal. The cable at the other end by the throttle body could have been stuck or the throttle position sensor had an issue.

try removing the floor mat.. sometimes the mat gets caught on the gas pedal and as you apply the brakes it applies the throttle. It would seem that the harder you press the faster the engine races...

With an assistant depressing the brake pedal to prevent the wheel from turning, tighten the spindle nut to 164 ft. lbs. (223 Nm). The vehicle should not rest on the tires or move until the spindle nut is tightened.

Inspect brake booster vacuum line from engine intake to brake booster for leaks also inspect brake booster check valve, more than likely your brake booster is causing a vacuum leak to your Intake thus leaning mixture wich increases idle rpm

have your ear brakes checked and or replaced. Possible worn pads. There is a worn indicator on the pad that scrapes the rotor when your brakes are worn. If they arent worn, have them inspected!!hopefully this helps!!

That could turn out to be a bad bad probblem, I would take the vehicle to a mechanic as soon as possible and have him fix the motor mounts!!!

Brakes need replacing. Just take the wheel off and have a look see.

Ask your mechanic to check the brake booster!