SilverShadow03

iTrader: (19)

Here is a great 'Boost Leak' - How To link TedB (GURU) posted recently. It is very informative and might help you out...

https://www.evolutionm.net/forums/ev...g-how-why.html

4xforce

iTrader: (25)

That's the how-to I followed and you'll notice nowhere in the thread did it say anything about TDC being required or what to do when having problems charging the system to the desired psi.

TommiM

iTrader: (19)

You can fiddle around until you get #1 cyl at tdc, but that doesnt mean the other 3 will be tdc. Your just testing for leaks in your intercooler piping and through tb shaft seals. The tb shut will hold enough for you to test the system with decent air supply. If you arent building pressure in the lines then either the air supply is too weak-- I used a portable air compressor that wouldnt overcome a small leak so it only went to 13 psi. Hooked it up to shop air and was able to pressurize it fast enough where I could find the leak.

lcwjr

iTrader: (4)

I would follow Ted B's advice. He's very clear in everything he posts. If he didn't advise using the TDC location, it probably isn't necessary. I didn't, and had no problem doing the boost leak testing.

You may not be able to reach the desired boost pressure if you have a leak. As I mentioned previously, my injector seals were leaking and I couldn't get past 14 psi until they were replaced! Only then would it hold enough pressure to allow me to discover that the PCV valve was leaking, and allowing intake manifold pressure to enter the cam cover. After I fixed that problem, I found out that the throttle shaft seals were no good. Each "fix" resulted in the ability to hold a bit more pressure until I reached the boost level (psi) I wanted.

4xforce

iTrader: (25)

Thanks for everyones time and help. I know the injector seals are leaking so I think I may just wait until I get the new injectors installed. Might as well order a new PCV while I'm at it. Thanks again.

ethan169

iTrader: (3)

I came across this thread and was about to comment saying I had the same problem. Glad you found my thread and hopefully it helped you out a bit.

I have come to the conclusion (sort of) that it is my PCV valve. I havent yet replaced it though. Im ordering through russel at Mistubi****parts.net and I wanted to order a whole bunch of stuff at the same time. Still putting together my parts list....

Anyway most likely that is your problem too. Give it a try and definitely report back with any results.

Ive done a lot of research on boost leak testing and trying my own things over the past 3 years. For such a simple test its hard to get solid answers. As you have found out everyone seems to do it different with the same results.

Good luck!

Ethan

4xforce

iTrader: (25)

Ya no kidding. No solid answers is right. I am putting together an e85 setup and will be running about 28-30 psi. Feels like I may never get to a point where I can test it to that psi. Since I am installing injectors at the same time I feel like I may just end up buying the replacement parts that I would likely have to replace if I have a leak and just take them with me when I get the injectors installed and have the shop who installs them take care of it. I hate doing that but I have yet to see a reputable tuner or the like (not knocking anyone else who has posted here) chime in and tell me what my dumb *** is doing wrong. I'm very certain there are quite a few on here that could lead me right to my issue.

ethan169

iTrader: (3)

Yeah I hear you on that.

For example that tube that goes from your valve cover to the intake pipe that everyone says will leak some and you should just plug it up is pressurized for the same reason why your oilcap is leaking pressure as well. Yet every one says its normal for that tube to have pressure and to just plug it up but the oil cap shouldn't have any pressure at all. This doesn't make sense to me at all. Im also 99% sure its not my valve seals as the when i did my cams and valve springs the seals where super tight and seemed to be in great shape...

Anyway its a crap shoot. Good luck on the E-85 I wish i had a station closer to me. I my give it a go and just buy a larger tank to fill up every once in a while.

-Ethan

EvODavO

iTrader: (8)

If it's the PCV valve shouldn't you be able to check by clamping off that hose from the intake manifold to the valve cover while pressurizing the system?

ethan169

iTrader: (3)

Good point. I would say your most likely correct. Ill have to try that I suppose. I was just going to replace it because its only 20 bucks and its the original one that has 66k on it..

Thanks for the idea.

-Ethan

EvODavO

iTrader: (8)

As I said earlier in this thread I'm also having the same problem. This seems to be a common issue. I'm sure there's a good reason why all of this air is pouring out of the breather valve and it's probably an easy fix. When you find the fix please post it up for us and the future searchers, I'll do the same.

ethan169

iTrader: (3)

Will do for sure...

Have you tried replacing your pcv valve yet? I have only read about one other person doing that and it was on the first page i think. He said it actually made it worse? Ill confirm with mine soon hopefully.

EvODavO

iTrader: (8)

No, but I have tried the MAP crankcase vents which have a check valve in them so I'm assuming it is not a problem with my PCV valve.

lcwjr

iTrader: (4)

Not sure if you were referring to my post. To be clear, the original PCV valve was leaking, and allowing intake manifold air to blow back into the cam cover. I don't remember exactly, but I believe it was leaking from about 10 psi and up. I bought a new OEM replacement, and it was leaking even worse. I then installed the check valve between the PCV valve and the intake manifold. That fixed the problem. By the way, you can't just replace the PCV valve with the check valve because the air passage in the check valve is way too large-the idle speed will race up. Ask how I know.

EvODavO

iTrader: (8)

4xforce and Ethan, what are you guys using to pressurize the system?



This is what I am using to test for leaks. It's only 1/2 HP but should be sufficient to get over 20psi, right?