subject says it all...how do you guys find vacuum leaks and whats the best way?

 

turn it on , put your lips to the end and if it starts making noise elsewhere then , you know your vaccuum leaks ......I couldn't resist ...cheers

 

thanks i never thought of that...smartass

(its ok though, i would have said the same thing in your situation)

 

spray each hoses with carb cleaner. if the idle change, then you got the right one. carb cleaner will seal the lines for a few seconds.

 

replace all the houses and you won't have to find them. Extreme but it works.

 

just rip them all out until you only have the one for the brake booster. then you only have one to worry about.

 

Some people... Simply spray carb cleaner around the engine, on spot at a time (with the car running) If there's a leak, the idle will raise significantly. If you dont have carb cleaner, go buy some. NOW! I can wait.

 

thanks, that sounds like an easy and good way to me, im on my way to schucks to get some carb cleaner...woohoo

 

get a stethascope from the doc. and listen for hissing

 

that might work but...
right now my engine sounds like a lawnmower, i think its missing a gasket somewhere on that damned exhaust manifold (or maybe a hole) but either way id be deaf in a good 30 seconds if i used a stethoscope...ouch

 

I thought carb cleaner would make the revs *drop*.... I know the carb cleaner that I used (to clean the carb) made the revs drop..

Anyone?

Jon

 

I think the reason the idle speeds up when you spray carb cleaner around a leaky vaccume hose is because the leak is temporarily sealed up. Idle speed should jump back up to where its supposed to be for a sec. (assuming its idling low because of the leak)

yea, carb cleaner will cause your idle to drop if you spray it in the intake.

 

Okay, now I'm even MORE confused..


I thought vacuum leaks increased idle... 'cause when I posted about my car revving unexplicably at 3500RPM and not coming down, folks said "vacuum leak". ?

And I thought that only certain types of carb cleaner made the engine rev higher when used to test leaks.. and that most made it lower... ?


Jon

 

If your vac leak is not HUGE & your car is running a bit rich (like an RX7), than a vac leak will increase the idle speed.

Idle speed increases when you spray carb cleaner on a leak NOT because the leak is sealed, but because the flammable liquid is combusted by the engine.

I'm a professional mechanic & have a good reputation for not destroying people's cars. I DO NOT use carb cleaner. I use a bottle of propane with a 1/4" hose & wand, , about 6' long. Carb cleaner is toxic, corrosive & dangerous. It runs downhill because it's a liquid, will get on hot surfaces & at best give off noxious fumes, at worst catch on fire.

Best of all is a "smoke machine" or "smoke generator". I reccomend everyone who can afford it, especially turbo'd cars, have their system "smoked out" on occaision. You will discover air leaks you never knew you had. Simply an amazing piece of equipment.

j.p

 

oh good im gonna try that, my car seems to rev at 1500 for no reason.

 

Thats the same case after i did my rats removal. I just said, "Screw it" and ordered a webber and intake!

 

im confused about the smoke system, what exactly are you doing with the propane? I was gonna use a propane torch without the flame going and run it along the vacuum lines because i have heard the propane will kill the engine...so when engine dies, you have found a leak.

but im not following what satanicmechanic is talking about with the smoke machine...

 

How much did this setup cost you and where did you get it dude?

 

Here's another "tool" for locating vacuum leaks, brought up a little while ago in a thread titled "Find those vacuum leaks".

https://www.rx7club.com/showthread.p...hreadid=264223

 

Yeah, the smoke machine is the way to go for a professional.

You can buy smoke f/x machines at Kmart that makes smoke for parties. Rig up some hose on it and with a little duct tape you are ready to roll. One 2,000$ Snap On smoke machine ready to go!

It is also cool for parties and Halloween. Runs about 60$.

Hope you find them all!!

 

Or use an unlit propane torch. Carb cleaner can puddle if you're not careful. Unburned propane should blow away. Go slow and dont use too much.