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AllShoNoGo
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Discussion Starter · #1 ·
taken from another site

*This one is more specific to a 2.0L*
So if you have read around you will know that a boost leak = vacuum leak. Well, the idea behind this test is to create enough pressure until you hear/find a leak.
Here is what I used:
Valve Stem from tire
2" Qwik Cap (Lowe's and Home Depot carry these in the plumbing dept.)
ABA MAF (I kept this old dead one)
Drill and drill bit (forgot what size)
Air compressor
Tire Pressure attachment
Spray bottle with soap and water
Here is what to do:
1. Acquire at least the Qwik Cap or whatever it's called
2. Acquire 1 valve stem with a good shrader valve
3. Drill a hole the same size as the tip (where the cap goes) in the center of the Qwik Cap
4. Pull the valve stem through
5. Attach the 2" Qwik Cap with valve stem to the side of the MAF with the "grid" on it
6. Remove the boot/clamp from the MAF that is installed in the car
7. Attach your "pressure tester" here and tighten the clamp/boot onto the MAF
8. Using your tire pressure attachment, send compressed air into the engine. (I blocked the TB open by using a long screw driver and putting one end on the TB and the other on the exhaust manifold.)
9. Listen for leaks. If you suspect a leak, spray the soap and water around the area and look for bubbles.
I found a leak at the TB where the intake boot clamps onto the TB. Tightened the clamp, no leaks! I started to hear the oil cap leak a little too.
*Note, don't pressurized the system too much. You will pressurize the crank case. It won't take much to find a leak. I know my OPG is already leaking so I didn't care.


Also another trick

Start Engine
Use a propane torch (do not light it.)-turn valve on....
Pass the nozzle around your intake tube, vac lines, and all intake connections...
The idle will rise/smooth out when the torch passes a 'leak'
 

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Let's say I don't have an old MAF to use. Could I just pressurize the vacuum system from the hose that connects to the MAF? I really don't want to buy a part just to destroy it.
 

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Another good way to find a vacuum leak if you are a little brave is to use a can of ether. Follow your lines around and just do little spritzes of ether. When you find your leak your engine will rev up a little bit from the ether making it's way into your engine.
 

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Probably the BEST way to find vacuum leaks is utilizing the smoke test. You can use one of those little units that the DJ's use.
 
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