low vaccum at idle

[wildacexxx]

i've been hearing lately that i am suppose to have 20 psi vac at idle. well my car has only mustered at most 11 psi at idle. im sure i have a vaccum leak but how do i check for them?

[ILikeMy240sx]

You need to pressurize the intake system. Basically, get a cap that will go in the intake pipe instead of the MAF. Drill out the cap, install a tire valve stem. Now install the cap in the intake pipe, put a clamp around it and use an air hose to pressurize the intake system.

You can either hear a hiss when theres a leak or spray windex everywhere and it will bubble if there is leak.

[wildacexxx]

i thought that was only for boost leaks. vac leaks also?

[Pepperoni]

If you need one i have one. Professionally machined. No home made Home Depot crap that will leak on you. Comes with couplers and clamps.

By the way, you're not supposed to attach it to your intake if you have a catch can/have the intake connected to your valve cover. Connect it to your turbo inlet (disconnecting the intake completely).

[ILikeMy240sx]

i thought that was only for boost leaks. vac leaks also?

boost leak or vac leak.. leak is a leak. if it leaks during vac it will leak during boost and vice versa. hole is a hole.

[Driver11324]

can I see a pic of this cap. I have the same problem with low vac at idle.

[Pepperoni]

can I see a pic of this cap. I have the same problem with low vac at idle.

Sure, i snapped a few pics here at my desk

Bead-rolled

Bushing in between to prevent leaks.

Complete kit

Any questions just let me know

[Driver11324]

so the cap raplaces the mafs?

[srpowered240sx]

no, you take the intercooler piping off of you turbo ("hot side" piping) and attach it there. pressurize it with a air hose, just like inflating a tire, have a friend watch the boost gauge, to make sure you dont go overboard. disconnect and listen..........hssssssssssssssssssssssssssss find it, fix it.