Odd vacuum problem

[DylanM240]

Hey guys, I seem to have a very weird vacuum problem going on. I swapped a blacktop sr20det into my s13 last winter and the car is running just fine, but recently I have (finally) installed a boost gauge and for some weird reason, my vacuum sits at 0 when it's not making boost, never any negative? The car makes the stock 7psi just fine and I also replaced EVERY vacuum line while doing the swap, following the factory diagram. The only blocked off port is the one under the throttle body which is plugged with a screw, ziptied on both ends(definitely no leak) The other super weird thing was, we hooked up a MBC which was working out of another car and when we turn the boost up, it's actually cuts boost(NO it wasn't installed backwards hahaha)

So I am just wondering what would cause this? The car runs perfectly, makes 7psi of boost but never reads below zero, not while driving before boost range or at idle.

[compactfean]

Sounds like your not t'd into the intake manifold for the gauge or gauge is faulty.

[DylanM240]

My gauge is running off of the intercooler intake pipe(stock SMIC setup) and it also meets up with the wastegate actuator vacuum line(tee is running from wastegate actuator, one side to intake pipe other is boost gauge) Is this improper? We ran the boost gauge in between the intake piping and the t from the wastegate actuator if that information is needed as well. I did check on how to hook the boost controller up, but I figured the boost gauge would be fine hooked up to those lines as well(It read 7psi before and after the MBC was tried)

Also, when the boost controller was hooked up and "set" to 9psi, the gauge would read about 3psi and the car felt less powerful. The MBC is a turboxs.

[compactfean]

Boost gauge should be hooked up straight to the intake manifold as well as fpr and bov. your wastegate and boost controller should go like this, ic pipe-boost controller-wastegate. a ball and spring style boost controller will give more accurate control of your boost (yes the $20 e-ebay or diy boost controllers work better)

[DylanM240]

Boost gauge should be hooked up straight to the intake manifold as well as fpr and bov. your wastegate and boost controller should go like this, ic pipe-boost controller-wastegate. a ball and spring style boost controller will give more accurate control of your boost (yes the $20 e-ebay or diy boost controllers work better)

So. I should tee my boost source from the FPR? My "bov" is the stock recirc valve so I'll trace that back and see where it hooks up again.

The turboxs is a ball and spring controller since it was a leftover electronic controller, not the lower performance bleeder valve. And my boost controller should just be in line from the IC pipe to the wastegate vac source? Nothing else in that line?

[DylanM240]

After some re-routing and advice you have once again fixed my problem, you're the man compactfean.

[compactfean]

Sweet! Glad to hear.