After reading a few posts about finding vacuum leaks, I did my own check.
I went to Lowes and bought a 2" PVC peice and an end cap.
I drilled out the cap with a 1/2" bit. I made my own tap by cutting groves into a spare 3/8" NPT fitting. I cut the threads into the end cap with it, then used a new one with lots of Teflon tape to seal it in. I used PVC cement to join the two pieces...instant pressure checker.
Next I removed my intake (HKS RS). I secured the pressure checker to the turbo inlet, connected my air hose and dialed in 10psi of pressure from my air compressor.
I immediately heard hissing.
1st leak was the pressure line going from the compressor housing to my HKS EVC boost sloenoid. It was leaking BADLY at the housing. I replaced the entire line with a new, smaller line (4mm I think), and double zip tied both ends.
The next leak was my Turbo XS H34 (recirc) BOV. It was seeping. I checked it by spraying water with a little dish soap in it. I removed it and cleaned the seat. After reinstalling it still leaked a bit, but not as bad. I think if I use some valve lapping compound it will completely seal.
the last one has me.
It's leaking at the throttle body, at the butteryfly shaft. If I giggle the shaft, I can hear it leak more and less. I'm not sure what to do? Can it be rebuilt with new bushings? It's not too bad, but I think it is actually a vacuum leak during non-boost times. My idle sucks, I do have 272s but I have cam gears set at -4/-1.

I also sparyed the soapy water over the entire boost circuit, from turbo, IC pipes, IC, BOV and all vac lines. Also the fuel injector seats.

I didn't even think I had a leak and found 3. I suggest this to all. Cheap insurance. Cost less than $5 for the parts, as long as you have an air source.

 

Did you had to put the engine at TDC? The I also heard hissing at the throttle body when I did a boost leak test. Not sure why though.

 

awsome... u prob read my post last week on it.. my cars at mitsu getting the injectors checked out and i bought an MR BOV.. I cant wait to feel the difference. Excellent ingenuity on your self made leak kit...

 

I didn't put engine at TDC, because there is going to be a vavle or two open pretty much any crank position.

 

EvoRS, yes, your post was the final one that convinced me to check. Glad I did nad found the leaks.
Please post if you check out the MR BOV for leaking.

 

Good deal.. its like having your power back like new

 

So bishi does your car run better now,can you tell a difference.

 

don't quote me on this but I think you got lucky. The engine could have been close to TDC when you did the test. When I try testing without the engine at TDC I would not get any pressure. I didn't want to bother with the TDC so I cap off the upper pipe. Pressure can now go to 20 to 25 with no problem.

Glad you found the leaks and it should make a difference.

 

what is tdc?

 

Top Dead Center.

 

True dead center, there is a mark on your valve cover that shows this.

Shane

 

There are 2 marks one on the right hand and left hand side of the valve cover right above the cam gears, there is also Marks on the Crank Pulley.

 

It is alarming how many evos have boost leaks

90% of the time when customers are complaining about how their flashes are running they either have a boost leak or a leaking bov - the other 10% is spark plugs and fuel

 

No my car isn't idling any better.
I think I may have a bad injector.
It has been an on-going problem 1st found by Big Al and myself on a custom flash he did for me.
It meets all the symptoms of a bad injector, poor starting, bad Idle, poor mileage, and it clicks sometimes (My #2 injector). They are PTE 680cc DSM injectors.
When I'm in the gas, it runs fine, just sucks starting and idling. I've noticed my AFR between 19 and 17:1 until it warms up.
After it warms it's much better but still isn't very smooth, up and down.
I did go to colder Denso plugs, that could cause the poor starting and cold idle.
I'm going to send the injectors to RC just as insurance.
Any other thoughts?

 

It's a little unclear exactly what I'm seeing in the photo. Is that a single end cap? The diameter of the PVC is 2"? You were able to wedge this into the turbo inlet?

It's a good idea.

BTW - With HKS 272s and -4/-1.5 setting on the cams, the car should idle like a stocker.