MBC will not go below 15 psi...

[JOSIEONETOOTH]

Yes, I have searched tirelessly, with my joe p mbc turned down all the way, i am still hitting 15 psi on my t25. When running a line straight from the compressor to the wastegate, i only hit 10-11. Is it possible that the mbc itself is just causing a delay, the spring is too stiff to go any lower, or is something weird going on?

 

[92AWDHX40]

Well with any boost issue did you do a boost leak test? One thing you should do to rule out ANY leaks, then you know thats done.

 

[JOSIEONETOOTH]

my injector seals are the only thing leaking(getting new injectors soon) but boost control is not a problem when running a line from compressor to wastegate

 

[99ECLIPSEGSXDSM]

How long have you had the mbc? Did you buy it new or used? Check te vacuum lines! Even if there's a tiny pin hole in the line it wont boost properly!

 

[92AWDHX40]

So there are no boost leaks anywhere other than the injector seals, those are a easy fix, and cheap.

 

[GSLENK]

You sure you didnt hook it up backwards? It'll act like that if on backwards, somewhat.

Does it adjust above 15psi?

 

[JOSIEONETOOTH]

vacuum lines are good, made the shortest route possble for the mbc, pretty sure its hooked up right(bottom goes to compressor and the side nipple goes to wastegate, and i bought it new and yes it adjusts above 15.

 

[Mitch41]

I have mine (Joe p) only twisted like one to two turns (least i could do without fear it would blow apart) to get it to boost 12 psi. The springs are pretty stiff I think.

 

[JOSIEONETOOTH]

mine is turned down all the way

 

[Hal]

1) You can't run less than waste gate spring pressure on an OEM style actuator

2) Inter cooler pressure drop effects boost control when using the compressor housing as the source

3) Not all mechanical boost gauges are equal. You'd be surprised at not only the margin of error for a given gauge but how inaccurate some of them really are.

 

[Eclipse2630]

i had this same problem and come to find out it was backwards...

i do know that sometimes, not often, they can just get worn out or they can be defective. little metal ball and spring.. kinda easy to break or not made correctly

 

[JOSIEONETOOTH]

well im starting to suspect it being faulty or the spring being a little too tight then because everything else checks out

 

[4CEDinduction]

sounds like to me, you have a hole in one of the hoses from your turbo to wastegate to the MBC. Also what kind of bar and spring do you have in your wastegate? You really dont need a MBC if you have an external wastegate. You might want to try just bypassing your MBC.

 

[Eclipse2630]

sounds like to me, you have a hole in one of the hoses from your turbo to wastegate to the MBC. Also what kind of bar and spring do you have in your wastegate? You really dont need a MBC if you have an external wastegate. You might want to try just bypassing your MBC.

idk about the hole in the hose, i thought the same before i found out mine was backwards. before i fixed it i hook my hoses back up to the stock boost solenoid and boost was set back to stock. hooked it back up how it was before. was up at 25 pounds. switched the lines around to mbc. plug and play from there..

its possible inspect your vacuum lines bro. do u still have the stock boost solenoid? if so hook it back up and see what happens. if it works good and puts you back to stock, if you havent already take a wood screw and remove the restricter, that will give you 1-2, maybe 3 pounds more until you can get a new mbc if it is indeed faulty.

be careful not to break the nipple off the stock boost solenoid. you only need to get it in a little bit and pull to remove the restricter.

http://www.dsmtuners.com/forums/newbie-forum/360629-waste-gate-solenoid-bosst-control.html

 

[compression]

The spring is probably too tight, you can cut a coil off of it, or two. the same applies if your mbc wont accurately go higher (like up to 17 then completely shut 50psi ) and in that case you can stretch the spring to compensate.

 

[Eclipse2630]

The spring is probably too tight, you can cut a coil off of it, or two. the same applies if your mbc wont accurately go higher (like up to 17 then completely shut 50psi ) and in that case you can stretch the spring to compensate.



If i am reading correctly he isn't using that solenoid anymore, he has a totally separate manual boost controller, which bypasses that.

yeah i know but he suspects that its faulty. i was giving him am alternative just in case it is faulty. he has a 2g, the stock boost solenoid should still be in his engine bay still plugged into the harness or it throws a cel. just sayin..

 

[CrawlinZX14]

or there is always the other option. he doesnt have enough threads into the mbc and its leaking boost strait out the set screw. cut a coil out of the spring, and see what happens. U can cut 2 coils off and thread in a bit more of your MBC. You can always stretch it out a bit to add extra tension, but if its to long to start, then you can have issues.

 

[Eclipse2630]

thats what i love about dsms you more than likely always have more options haha