Engine Cutoffs
Thread Starter
Heel & Toe
Joined: Jul 2008
Posts: 21
Likes: 0
From: Clinton MD
Engine Cutoffs
I have a 1986 4+3 and everytime you apply a lot of pressure to the brakes the car cuts off. It cuts off while idling and while driving. I replaced the master cylinder and the brake booster. Anyone have any thoughts, or could the new booster be bad also.
Thread Starter
Heel & Toe
Joined: Jul 2008
Posts: 21
Likes: 0
From: Clinton MD
It cuts off while idle also while driving, more when I am pulling into a parking lot and braking it cutts off. I can make it cut off when idling by just pushing the brake. The rpms when drop and it cutts off.
Team Owner
Joined: Jan 2003
Posts: 20,306
Likes: 242
From: Summerland B.C. Canada
Plug the vacuum hose to booster and see if you can kill it at idle. If you can, you can rule out the booster.
Have you tried to set the minimum idle and re-adjust the throttle position sensor, according to the factory service manual ??
Have you tried to set the minimum idle and re-adjust the throttle position sensor, according to the factory service manual ??
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Team Owner
Joined: Jan 2003
Posts: 20,306
Likes: 242
From: Summerland B.C. Canada
Cheaper to diagnose the IAC. http://members.shaw.ca/agent86/IAC.pdf
You might want to spend the time and pull the TB, remove the IAC and clean the passages and bores. Re-install and then re-set the minimum idle and TPS. https://www.corvetteforum.com/techti...D=55&TopicID=2
You might want to spend the time and pull the TB, remove the IAC and clean the passages and bores. Re-install and then re-set the minimum idle and TPS. https://www.corvetteforum.com/techti...D=55&TopicID=2
Thread Starter
Heel & Toe
Joined: Jul 2008
Posts: 21
Likes: 0
From: Clinton MD
I changed the idle control unit and it did help a little. I am being told now that it is the vacuum. The cams were changed by the previous owner. I am told I need a vacuum canister in line with the brake booster.