Hi,

I've recently removed the MBC that was installed in my car and i reconnected all the hoses back up.

Took the car for a quick spin and now it will only boost to 11-12psi, which i am told is the maximum actuator pressure.

What could the problem be?

P.S I've used the aftermarket hoses that were used with the MBC and there is no "boost pill" in these hoses, could this be the problem?

Maybe a diagram of how the solenoid should be connected would help? (pretty sure it's all correct though.

Any help would be greatly appreciated as the car is an absolute slug @ 11psi.

 

If your running with aftermarket upper and especially lower intercooling piping along with an aftermarket exhaust (most common 3" turbo-back), it is a significant difference in what your boost will be vs stock piping due to the bigger diameter of the new aftermarket piping. Even a good aftermarket frontmount will drop your boost about 1-3 psi alone. So if that is the case, you need a boost controller to reach the deserved boost you want.

 

If the only thing he removed is the MBC that would not be the problem. The boost pill would be the more likely culprit.

 

yeah, did u reuse the stock vac hose? don't use the stock one, replace all with new vac lines.

 

Anybody that has installed aftermarket fmic piping and exhaust and watched their boost gauge before and after will confirm what I said. Good example would be myself 2yrs ago, which I really didn't get it at the time til after doing some research and my buddy had the same issue in his boost after his installed aftermarket fmic piping and exhaust. So I'm just giving some advice that happened from experienced and not a thought up prediction to what his problem might be.

 

I used the vac hose that came with the MBC and that doesn't have the boost pill.

Could someone please explain how the boost pill would create more boost?

 

mmm okay another question is, what kind of MBC u running? if is hallman they should have a hard spring that u gotta put in, the soft spring push around 11 max i think.

 

I was running a Turbosmart "style" MBC. Basically a screw on top of an aluminum body with two nipples on one side.

 

Why remove a working MBC?

And yes, your problems are from not having the correct boost pills in the MBC vac lines. The boost pills control how much vac the solenoid works on.

To get it working on the solenoid you have to use the factory lines w/pills.

Tvo - his issue is the pills.

 

wow i misread this whole thread, i thought u are having problem with the MBC. my bad, yeah if u put everything back you have to use the stick vac line like SmikeEvo said!

 

The boost pill / orfice restricts the flow of air to the wastegate actuator. With it removed, too much airflow makes it to the actuator which causes it to open the wastegate sooner.

Best bet is to order a new setup of boost lines with pill from the dealer, reuse your original boost lines with pill, or re-install your mbc.

 

as others said

you need OEM boost lines

plain and simple

 

Just go down to your local Mitsu dealership and purchase the factory boost/vacuum line assembly. It is plug and play. It includes all the hoses cut to the proper length, the two boost restrictor orifices(pills) preinstalled in their resective specific locations, the necessary vacuum "T" which is also preinstalled in the appropriate location, as well as the necessary hose clamps.