trailblazer

I had my brake master cylinder off the car, with just the brake booster on. brake booster had its vaccum lines on it and everything, but had no master cylinder on it. anyway I started the car for a friend who wanted to hear it idle and it idled at 2k for some reason . could it have been the brake booster? 1995 del sol si d16z6

it was a steady idle at 2k, hood was closed and i couldn't hear much over the exhaust. my friend was like woah its idling at 2k so i turned it off. 80 degree cold start. didn't sound bad tho

Former User

What else were you working on under the hood?

trailblazer

I haven't really touched anything else.. also these wires are damaged on the drive side floor

kp

Sounds like the brake booster vacuum line was just a massive vacuum leak. Try disconnecting the vacuum line from the booster and plug the hose (bolt, your thumb, whatever), start it up again and see if it's back to normal.

forbiddenera

Those wires shouldn't have anything to do with your issue, but I would address them, looks like a fire hazard waiting to happen. Those wires should feed your rear speakers, tail lights, etc.

trailblazer

for ***** and giggles check out the manual conversion haha... it shifts beautifully tho good bracket good everything surprisngly. also yea the car was idling fine befor i took the brake cylnder off. i lost the bolt under the hood too! right under the master cylnder its jammed in there somewhere.. so new MC is waiting to be put on and i started her got a high idle for the first time
this is where I dropped the bolt and also old mc gasket where these lines runs down I doubt it could be causing a problem but yea

trailblazer

thank you all my rear lights work but I'll fix that asap

would no brake MC attached cause a leak? this is what I need to know. im lazy to see if it fixes my problem but that's a good way to test.. thanks tho. I have to somehow find the mounting bolt I dropped and install the new mc I guess.

mk378

YES. Ordinarily the front (facing the master cylinder) section of the booster holds vacuum. With the cylinder removed, that hole where it attaches is a massive leak.

Be sure to put the black rubber vacuum seal into the hole in the booster between the booster and the MC. This part usually comes with a new MC. It is sensitive to which way it faces, it should be marked "Cylinder Side" or similar.

If you lost one of the nuts for the cylinder studs it is just an ordinary M8x1.25. Be sure to use a lock washer too.

kp

Too lazy to unplug one hose? Good thing you started this thread.

mk378

Or start a car that is missing some parts and wonder why it doesn't work right.

Former User

Given that OP is uninterested in answering his original tech question, the thread no longer has a reason to exist.

OP - Please don't create threads that waste the time of members who seek to help and are actually interested in an answer.