MBC not working keeps boosting

[WIDSM]

When I purchased my car it had an homemade MBC, which did 11psi, even with it cranked in all the way. So I researched into why it wouldn't up the boost. I realized that it didn't have the vent hole in it so I drilled a 1/32 hole in the wastegate end of the tee. Now I installed it hoping it would all be good now. But when I would get on it, it would just keep boosting until I let off. I turned it all the way out and still the same results. I hooked it up to the BOV/ wastegate and the compressor/ wastegate, both gave me the same results. The spring inside doesn't have very much tension so I do not think it's that. I know I've hooked it up right\, and even tried hooking it up wrong but all with the same results. Right now I'm running it w/o any BC, it works fine like that I guess but I don't always want to run 17psi. So does anyone have any advice as to what I should do?

 

[mach4g63t]

Check your wastegate to see if it's actually opening at all, or stuck closed. If it's moving freely and does under vacuum, then try a new MBC.

 

[WIDSM]

My wastegate does work when I don't have the MBC hooked up.

 

[mach4g63t]

Then get rid of the MBC. Maybe it's leaking somewhere or something. Check all the lines. I would say if the WG works w/o it that's your problem. Maybe it's bleeding air somewhere.

 

[WIDSM]

ok thanks I'll try it for leaks or just go make another cheapo for now.

 

[WIDSM]

Well I took it all apart and started thing, and I believe the problem was that the spring was too long. So I cut down and now the wastegate opens, but the boost will spike at 22psi and drop way back down. Also the bearing might be a little to small because when I plug the vent hole I can blow through it, or am I supposed to be able to? Do I need to make the spring shorter, or should I get a harder spring now and cut that one down?

 

[dontfeedphils]

Dude, 50 bucks for a decent MBC and you don't have to mess with that back woods piece of crap your talking about.

 

[coeclipse12]

hey I went to ci motorsports and got a MBC with shipping $20 bucks it works great