MBC 10psi only...

So basically, I have installed a boost controller successfully before on a car, however, this time it was my car. I installed a Joe P MBC with all the right hoses and fittings, so everything should have been fine. No matter how much I turn it (havent dont it ALL the way for fear of blowing something), it stays at 10psi. I cut some rubber and drilled a hole in two pieces to cap off the turbo outlet and the intake nipple. It isnt the gauge, so what could it be????

how about boost leak. have you done a pressure check yet?

not as yet. I teed the line into the BOV line, and the wastegate nipple, so i should be good. Maybe I should have capped off the soleniod and the intake and turbo nipple with REAL rubber stoppers made for that purpose, not just some ghetto ones i made. Would boost leak be the only possible reason? If so, where could I find rubber stoppers that fit on the intake/turbo nipples???

Your BOV is leaking. Do the pressure test if you don't believe me.

Well, I'll throw on a 1G BOV, but ive never had any problems with the BOV before, and the car only has 53K miles on it. I'll need a 1G in the future anyways, so I'll see how that works out, and, hopefully, it will solve my problems.

you mean to say that you've gotten above 10psi on a stock 2g bov?

actually, to solve that problem. i installed a generic boost controller on my 2g and it was only reading 10psi no matter how i cranked it and then later to find out that the boost controller was a max boost of 10psi. check the boost controller for labeling or something.

you mean to say that you've gotten above 10psi on a stock 2g bov?

I've seen 20 psi on a 2g BOV. I've never seen a boost leak so big that it limits boost to 20 psi. The car would be so rich it wouldnt even run at all. Jsut to be sure, you have the "bottom" of the MBC to a boost source, and the "side" to the WG actuator, correct? Certainly sounds like a MBC issue to me.

Yeah, stock I was running it at 12psi consistantly. Then, after I installed the Joe P MBC, its only reading and "feeling" like 10psi. I'm thinkin I should have plugged up the nipples with "real" rubber stoppers, not just some rubber that i drilled and made a hole in. checked all the connections and they are all tight and where they are supposed to be. btw, I'm using plastic tee to tee off the BOV line, but I doubt that would make a difference. Not bad for my car or anything for 10psi, its just confusing me a lot. Joe P makes good MBC's from what I've heard and know, so I doubt it is the MBC itself. Removing the honeycomb wouldnt make a difference either i dont think. Thought this was gonna be as easy as last time... :banghead:

Ok, I have a JoeP MBC on my 97 and I can relate just a tad....the relationsip between the number of turns and the boost is NOT linear. I turned the screw 8-10 times for the boost to go up from10-11. Then, in just ONE more turn, the boost shot up to 15. Half a turn more, I was doing 18. You have to be very careful with that.

I only turned it like 5 times, and then i stopped out of fear that something was wrong, cause it was in like half way or more. I'll try adjusting it more, and see if thats the problem, i bet it is. :banghead: brb after testing out what Shpyder said, thanks.

Well, just took it out, and i got it up until 12, which was where my base psi was. I was 4 turns or so away from the bottom of the MBC, so I'm thinking right now that there probably is a boost leak of some sort. I'm using some generic brand 25$ gauge, so maybe I should get a better one(autometer/apexi/blitz) Nothing felt wrong, and nothing sounded wrong, just felt normal at 12psi. Or do the last 3-4 turns in the MBC hold A LOT of control? Suggestions anyone?

ya that is what i was gunna say. turn it to both extremes and see what the results are.

well, went out for another ride and when its all the way out, its at 10psi. When its all the way in, its at the stock 12psi. Confusing for now, but I think I'm just gonna revert back to stock, and buy a better gauge(autometer), better hoses, and brass vacum Tee's, just to make sure that next time everything is right. Or should I just leave the MBC on for now on the lowest setting to save myself the hassle AND be easy on the motor? Anyone living by Thousand Oaks, CA wanna help me out... :1zhelp: ...?

well, just leavin it on at 10psi for now, and i checked all the connections, and they are as tight as prom night. So the only other possibility is the BOV. I dont know how it could leak so easily, but if it isnt the BOV...im screwed.

oh , and btw, is 22 vacuum reading on my boost gauge pretty bad. I hear most ppls are around 17, so I'm wondering....

More is better. Stock is 18-22 spec IIRC. You have it hooked up the way I said right?

This may sound odd, but take the MBC off and try to blow into the input (oopsite the adjustment screw, not the side) with it all teh way out and all the way in. Tell me what happens.

Well, the MBC has no problems cause I did the blowing test, and I've deducted that it MUST be the BOV. I tried hooking it up to the turbo outlet instead, and it gave the same results, except I didnt have to turn as much to get to 12psi, but it just stayed at stock with it all the way in. The only reason would have to be my BOV is leaking right?

Hard for me to tell from here. www.vfaq.com, pressure test that shit.