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Discussion Starter #1
Just a few facts about the car, it's running AEM tuned with a MAP sensor, blah blah blah. Anyways, been having this issue about a high idle and changing AFR's at idle from different times when it's started, very odd problems. Thought it was the lack of grounds(could still be, adding grounds while we speak) anways, I put my boost leak tester on today and I've got a huge leak around the intake area that I can not find. I have done the starter fluid test at idle and I can't get any change in RPM/AFR so I'm thinking it has to be leaking just under positive pressure. I'm thinking my tuner may of been tuning around this issue and that's why I get such a variance from start to start. Any extra secrets on figuring where it's leaking from? Thanks
 

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a way to add pressure and then soap and water in a spray bottle
 

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Discussion Starter #3
Adding pressure what I meant by boost leak tester and this leak is way too big to find it with the soap/water trick. Tried that but will make another bottle and try again, lol. It's a Exploder intake fwiw. Thanks
 

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vacuum test

have you check the vacuum tree and around it... as it's fairly close to the intake...Also check the brake booster check valve...Mine blew the back section out which took a little to find....are you hearing a hissing noise??
 

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I just installed an Explorer intake on my vert and had a big vac leak. Took the upper off and found that one of the had vac lines that comes out of the back side under the upper was cracked half way around. I snapped it off, drilled it out, tapped it and installed a $3 dollar barbed fitting.
 

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Discussion Starter #6
My vac tree and everything is in the fenderwell. I'm hearing a real loud hissing noise and with my air compressor set on 110psi I can only get the gauge on my boost leak tester to show 15-18psi so it's a pretty large leak. I'm going to pull the upper off to retorque the lower intake so I'll look it over really really good. I used to think it was a lot of blow by going by the rings/etc and coming out the back of the intake because I used to just have a PCV valve back there vented since I had a evac setup on the valve covers but the PCV hole is plugged off on the back of the lower intake and I'm still getting it, so that ruled that out.
 

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hunting down the leak

I'd try to remove all vacuum sources and see if theres still a leak...ex- block all your intake ports/vacuum sources and see if there problem is still there..if it is then pull the intake or look in that area before you start removing parts
 

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My vac tree and everything is in the fenderwell. I'm hearing a real loud hissing noise and with my air compressor set on 110psi I can only get the gauge on my boost leak tester to show 15-18psi so it's a pretty large leak. I'm going to pull the upper off to retorque the lower intake so I'll look it over really really good. I used to think it was a lot of blow by going by the rings/etc and coming out the back of the intake because I used to just have a PCV valve back there vented since I had a evac setup on the valve covers but the PCV hole is plugged off on the back of the lower intake and I'm still getting it, so that ruled that out.
so your pressurizing the intake when youre checking for the leak? youre trying to pressurize all the charge pipes from the turbo and the intake?

if you still have your rockers installed when you do this, if one of the rockers are down, all that air is going to go out the exhaust.
 

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Discussion Starter #9
Pulled the intake today and nothing was cracked/broken/etc. I don't know where it's leaking from but it's very very annoying. It sounds like the back of the intake to me though but I can't feel anything with my hand at all.
 

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if you try what I recommeded with the intake on..it will isolate the cause to either your vacuum tree or vacuum lines or the intake..
 
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