I used duct tape to cover the intake ports for both LIM and UIM.
The vacuum ports were plugged with rubber plugs.
Both are tested seperately.

However, I cannot hold vacuum with Mity-Vac pump. You can see the duct tape cave in as I use the vacuum pump, but it doesn't hold it.
When I tried 10psi of pressure, you can see the duct tape bulge out (and hold), but the pressure leaks out.

So, could air be leaking through the duct tape itself? I made sure it's sealed around the ports. I do not "hear" air escaping through the BAC nor the IAC.

Is there a better method? Basically, I'm trying to test the components seperate to be "known" good before I re-assemble the intake manifolds.

Thanks,
J

 

do you have any of the emissions gear on there? turbo? na? s4 s5? some of the stock setups actually wont hold vacuum, due to the way they route some of the emissions stuff

 

Sorry for the lack of details.

These manifolds are from non-CA 89 NA.:
-Only things on the plenum is the BAC valve, fuel rail/injectors and seals, and VDI. All lines (air bleed, vacuum source for oil injector) are plugged except a vacuum port for the mity vac or air gun.

-LIM only has ACV capped and brake booster capped. I use the air bleed port for the mity vac or air gun.

Seal the intact tracts with duct tape.
It can't hold any vacuum reading, but it seems to keep the pressured air in the intake for some time (at least until the duct tape bulges settle).

I figured with any intake and most of the accesories gone or plugged, it would hold vacuum or pressure.