I did a simplified sequential and emissions removal and i think i have an air leak someplace... can someone tell me how to test it?

Alex

 

idle the engine and spray carb cleaner on vacuum lines or possible vacc leak spots. If idle changes then you found your leak.

Another way is to pressurize the intake system and use soapy water and look for bubbles

 

I used a smoke machine on mine today- found one at back of intake manifold instantly. However another way is to idle engine and listen with a 5/16'" hose 2-3 feet long. Its amazing the noise you can pickup using a simple hose. Another way is to remove the brake vacuum hose from your intake manifold, and apply light compressed air and listen with hose or feel around with a wet hand.

 

I disconnect both intakes and use two rubber expansion plugs hose clamped to the turbo inlets.



Then I feed compressed air into the hole the stock BOV used to occupy on the Y-pipe with a rubber bung that has an inner-mount tire valve stem stuck through it. You have to turn the crank pulley until the motor is in a position that all the air isn't escaping out the exhaust at which point you will pressurize the entire vacuum system. You can usually hear/feel the leak but if not, a little soapy water will do the trick.

 

Some vacuum leaks won't show up in a pressure test. I prefer to spray starting fluid around components that you think could be leaking, the engine will rev up and smooth out when it sucks it in.

Dale

 

I've used the starter fluid method...works good. I like the brake Vac line method though...sounds like a nice alternative.

 

Spraying starter fluid into the engine bay of an FD just seems sketchy to me. I mean, my car runs great and I smell nothing, but spraying Ether near the turbos while it's running? I don't think I'd wanna do that, especially anywhere near my house! lol

What if you spray soapy water? Your idle will still do SOMEthing, right? I mean the leak will be detectable from the bubbles and/or idle change?

 

Well if you don't have common sense then you probly shouldn't be opening the hood anyhow.

It's not like consistently spraying starter fluid in 30 second intervals all in and around the motor while smoking a joint in a candle lit only wooden alfalfa garage

It's a tap spray here and there...simple as that

 

I dont have any tools to check for vacuum leaks... can i buy a pump. I noticed when i removed the vacuum line off off the air reservoir above the alternator i hear a loud woosh meaning its building pressure so will my theory be right if the leak is either at the EGR or lower intake manifold? The reason i think is a air leak is because when in neutral the rpms drop to 500 rpms and it stalls at times...

can I take the air filters out and blow air from my vac shop? or maybe from the air inlet next to the throttle body.

Alex

 

I like that brake booster line idea. Might try that on mine when I have time.

 

On using starting fluid, it evaporates VERY quickly. Many people use brake cleaner or carb cleaner, that sticks around much longer and can run and go everywhere. Starting fluid is much safer.

Just spray in small puffs.

Dale

 

Get a cigar, light cigar, smoke cigar, blow smoke into a line, look for smoke

 

There ya have it. Use your common sense and hose that **** down with Ether!! Make sure you get the spark plugs.

 

i think it might be a blockage of air rather than a leak

 

I currently have problems with less vacuum on idle (negative ~7,2psi) than usual and only reaching 0.4 bar(5.8 psi) of boost.

I tried to blow into the brake booster hose whilst turning the crank to find where I just don't blow out to the exhaust. Even when this is blocked, I can blow almost effortlessly into the hose and at the same time hear it come out somewhere in the Y-pipe. Is this normal? Are the UIM and the Y-pipe openly connected when the car is off?

The car has had a simplified (poor mans) non-seq done to it, and I do not have access to all the parts to restore this atm, so I have to work with what I have.

I've had the UIM off and checked everything I can think of for leaks, but my problem still persists.

Any ideas?

 

Check the lower intake manifold...

 

Take a ping pong ball (anyone will do) place the tip of a pencil on it and wrap the whole thing with tin foil, allowing the pencil to create a tunnel on the top of the wrapped ball. Then heat up the bottom of the tin foil with a lighter and when it starts to smoke and throw it in.

 

Like this.

 

For what? Are there connection between that and the y-pipe?

 

Note: I was out for a quick look, and noticed my air control valve was leaking. The hoses are since before removed so I found one of my boost culprits. The two hose connectors are now plugged and I've gained 0.1 bar of boost. Still missing .2.