mbc install engine acts up now

[pur97tsifwd]

ok i got a mbc from slowboy racing this is how i installed it i put the vacuum fitting with 2 holes (1 hole bleeder) on the waste gate the other on the j pipe off the turbo i have the boost controller set with the screw all the way out and my bov is hooked up like this the vacuum line goes to my intake manifold

when i went and drove my car i still have the stock boost gauge it hits 14 and around 10 or so the car will shake and stutter and i have the controller turned all the way down

i was told the bov is suppose to be hooked up to the j pipe but i only have 1 nipple

 

[SBR Joe]

ok i got a mbc from slowboy racing this is how i installed it i put the vacuum fitting with 2 holes (1 hole bleeder) on the waste gate the other on the j pipe off the turbo i have the boost controller set with the screw all the way out and my bov is hooked up like this the vacuum line goes to my intake manifold

when i went and drove my car i still have the stock boost gauge it hits 14 and around 10 or so the car will shake and stutter and i have the controller turned all the way down

i was told the bov is suppose to be hooked up to the j pipe but i only have 1 nipple

Try capping off the j pipe vacuum port and teeing it into the bov line, i always have good luck with it there. And also, you dont wanna go off the stock boost gauge, get an aftermarket one. Its a good possibility that it may be hitting fuel cut. The stock gauge is not accurate at all and could be boosing more than what you think. Our MBC's dont liek to do less than like 15 so its likely that its doing at least that. But also, if the screw isnt touching the spring it would be like running atmosphere on the WG. I will start at around 10 and creep to whatever it wants to. That could also be the cause of teh issues your seeing, which sounds liek fuel cut.

Joe
SBR

 

[Charlie90GST]

attach some pics of your setup.

 

[pur97tsifwd]

ok here are some pics of my setup

i screwed the screw till i didnt hear the ball rattle this time i will c if that helped

 

[pur97tsifwd]

also the bcs do you just unhook the vacuum lines and leave it plugged in?

 

[SBR Joe]

also the bcs do you just unhook the vacuum lines and leave it plugged in?

You can completely remove it if you want. Its doing nothing just being plugegd in.



Joe
SBR

 

[DSMunknown]

i was told the bov is suppose to be hooked up to the j pipe but i only have 1 nipple

Whoever to you that should be shot.

I don't understand what's so damn difficult. I see you have a 1G, but look at this link anyways. The same concept applies. Derek provides one of my photos at the bottom. It's very simple and very easy. Just look at the photo. If you have any other questions, please just ask.

Try capping off the j pipe vacuum port and teeing it into the bov line, i always have good luck with it there.


Joe
SBR

NO!!

You must be logged in to view this image or video.

Click here to see more of my opinions about this "idiot mod."

 

[SBR Joe]

NO!!

You must be logged in to view this image or video.

[/QUOTE]


Expalin to me why not, it has worked great with all the cars i have seen that way, including my own. It may not be the "best" way in your opinion, but i always had boost spike issues with it off the J pipe, its a bit more steady and consistent coming off manifold pressure. And that link, like stated by yourself is your opinion. Im not going any further with all this because i dont want to start a big bi*** fest, but i will leave it that you can do either. I havent been able to see and physical proof of it being "bad" to tap into a manifold pressure source and in fact, have had betetr luck with it, so ill stick with it.


Joe
SBR

 

[DSMunknown]

Expalin to me why not, it has worked great with all the cars i have seen that way, including my own. It may not be the "best" way but i always had boost spike issues with it off the J pipe, it seemed to be a bit more steady coming off the bov line.


Joe
SBR

You didn't even try to click on the first link I just gave, did you? Derek quotes Bruce giving a (brief) explanation of the thought process. Go back and click-n-read.

 

[SBR Joe]

You didn't even try to click on the first link I just gave, did you? Derek quotes Bruce giving a (brief) explanation of the thought process. Go back and click-n-read.

I did, but wont hurt to go from either. And it was suggested by myself as an alternative solution that "may" have helped out the thread starter. I have personally seen accounts of the manifold source having better control and have seen it on my cars when i hooked it up to the both of them to see any benefits. It wasnt a huge deal but it was enough to make me believe that going off a manifold pressure source is not bad, and was in fact, like stated before a bit more controlled. But regardless if our opinions differ, this is not a "how to hook up my mbc" thread.

To the original poster: Try backing the boost controller out all the way and see if it helps, i still think your getting false readings off the POS stock gauge and are overboosing to the point that your hitting fuel cut.


Joe
SBR

 

[pur97tsifwd]

ok i have backed out the screw and it didnt not help so i am thinking maybe it is bad spark im going to get new wires and plugs

this is how the car feels sometimes when i am in first gear taking off it will buck a little or hesitate when i go wot it gets about 5 pounds now and bucks and jerks real bad and also when i take a corner

idk if that has anythign to do with this or help any one with my problem but i have the evo 3 motor in my car with 510cc injectors and a 190lph pump and i am using the ecu out of the talon

I have taken my plugs out and looked at them they seem to be ok but i will still change them

 

[pur97tsifwd]

o also i have a 2g talon that i have modded and i know what fuel cut feels like on a 2g anyways its like a big bang and the engine stops for a sec then picks back up my 1g is not doing that if feels like it is missing or not getting enough fuel and jerks and stutters.

 

[SBR Joe]

Hmmm...sounds like your having other issues. How long have you had that walbro pump? it almost sounds like a lack of fuel issue, like if you were out of gas when it acts up going around a corner, or possibly a bad power/ground connection and is making crappy contact when under accelleration or in turns. Check your battery terminals to see if MAYBE they are loose. I had that issue with a car on the dyno before with loose terminals and chased it for hours before we found out that that was the issue.


Joe
SBR

 

[pur97tsifwd]

well i just put the pump in a couple days ago i have took it out yesterday to see if everything was ok it looks fine

 

[SBR Joe]

well i just put the pump in a couple days ago i have took it out yesterday to see if everything was ok it looks fine

Ya, not likely a fuel issue then. Check all your power/ground connections and all connectors off the harness to make sure something didnt get bumped or wiggle loose. Its kind of trial by error at this point.


Joe
SBR

 

[pur97tsifwd]

well i checked the fuses and battery they were all ok

 

[SBR Joe]

Did it only start doing this after the MBC install??



Joe
SBR

 

[pur97tsifwd]

well the first time i installed the mbc i put it on backwards and it would hit a full 14 pounds even with the screw backed out all the way and stutter and it gradually got worse so i tried switched the mbc the right way still does it. then i tried hooking up the bcs i hooked it up like so one side on the waste gate the other on the j-pipe still did the stutter so i put the mbc back on the right way and gave up

 

[SBR Joe]

This doesnt make any sense.... Disconnect the battery for a few minutesto reset everything, juts to start fresh, and see if it still acts up. Did you check for vaccuum/boost leaks???



Joe
SBR

 

[GVR4592]

Try capping off the j pipe vacuum port and teeing it into the bov line,

Don't ever do that, it's just stupid. You should never use the BOV line for anything other than the BOV. A bleed in the line can cause the bov to not function properly.

 

[GVR4592]

ok i have backed out the screw and it didnt not help so i am thinking maybe it is bad spark im going to get new wires and plugs

this is how the car feels sometimes when i am in first gear taking off it will buck a little or hesitate when i go wot it gets about 5 pounds now and bucks and jerks real bad and also when i take a corner

idk if that has anythign to do with this or help any one with my problem but i have the evo 3 motor in my car with 510cc injectors and a 190lph pump and i am using the ecu out of the talon

I have taken my plugs out and looked at them they seem to be ok but i will still change them

Have you performed a boost leak test? I think you should remove the mbc until you get a datalogger and a real boost gauge. It's really kind of pointless to do any modifications without them. The stuttering could be the ecu pulling a lot of timing because of excessive knock, and that's the easiest way to destroy your engine.

 

[DSMunknown]

Don't ever do that, it's just stupid. You should never use the BOV line for anything other than the BOV. A bleed in the line can cause the bov to not function properly.

Thank youuuuuuuu.

 

[1_bar_goes_far]

No one said it from what I saw skiming throught the posts, but on the stock 1g boost guage, 14 psi means nothing. It never can actualy hit 14 psi due to coding in the ecu, and also, it is just calculated off air flow, nothing more. So just because it says ~14psi, you can be running a million as far as it is concerned. So get a data logger and real boost gauge like said already. And also, thinking of that, it might be possible you damaged the motor when you went WOT the first time and hit who knows how much boost since you had it hooked up wrong.

 

[Talesin]

Seconded. NEVER tee off the CBV/BOV line, especially to a bleeder system. You want as fast action as possible... remember, it's what is keeping your turbo healthy. The faster it reacts, the less stress on your turbo, the longer it'll take to eat itself.

The reason that running the wastegate off the manifold pressure seems to help some people is that it assures you're getting a definite boost level at the manifold, regardless of how many boost leaks you may have. If you have a bad leak, you're going to overspin the crap out of your turbo, and kill it damn quick. Don't do it. If you have spike/creep, port the damn exhaust housing for better flow through the wastegate.


As for the original poster... boost leak test, and get a real boost gauge. It may feel like a 'pop' on your 2G, but my 1G shudders and jerks like crazy if I hit cut, it doesn't just stop dead and re-start.
IMO, sounds like you're hitting fuel cut for one reason or another. Find out why, and rule out the most likely first... overboosting due to the MBC, or a boost leak. Or both. I'd guess a boost leak to be likely, thanks to having the MBC hooked up backward. Backward ball & spring MBC = no boost reference to the wastegate = turbo spins out of control until you take your foot off the pedal, hopefully only rupturing an intake tract hose or popping one off a pipe somewhere.

Seriously, it is NOT SAFE to throw an MBC on if you do not have an ACTUAL boost gauge. It's also outright stupid.

 

[Generation X]

Try capping off the j pipe vacuum port and teeing it into the bov line, i always have good luck with it there. And also, you dont wanna go off the stock boost gauge, get an aftermarket one. Its a good possibility that it may be hitting fuel cut. The stock gauge is not accurate at all and could be boosing more than what you think. Our MBC's dont liek to do less than like 15 so its likely that its doing at least that. But also, if the screw isnt touching the spring it would be like running atmosphere on the WG. I will start at around 10 and creep to whatever it wants to. That could also be the cause of teh issues your seeing, which sounds liek fuel cut.

Joe
SBR

Teeing it into the bov line...

You guy's are about the third big shop now that has mentioned hooking it up that way.

Both.. Robert and Brian @ FP told me that they tee off of the bov line, as well as Robert from Road Race Engineering, so when you have big shops telling you that, I think I would tend to believe them.

There are so many heated debates about that subject on here it's not even funny.