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Mbc Question


Phil94850

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i purchased a Voodoo III MBC and installed per instructions. Im only able to get 10psi even if i turn the MBC all the way up. Ive tried swapping the hoses on the MBC and no change. For those of you that use MBC's have you had any similar probs like this? If not, what do u guys suggest looking for ? IVe checked my hoses off the turbo to the intercooler and all that and found no cracks or anything ? plz. help .. thank you

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I was going to say check the hoses but you said you did that, double check them...if that still doesnt work I remember reading somewhere that you have to remove the BCS (boost control solenoid) or something...Do some searching I am sure you will find the answer. As far as the BCS goes though I am not even sure if they came on the 94' models. Do you have any pictures so we can make sure you didnt put it in backwards or something? are you sure the MBC is working properly?

Also check all of your vacuum lines as they carry the pressure as well.

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i disconnected the BCS there is nothing hooked up to it except the electrical connector. I had a cheapy BCS and i thought that was my problem so i bought a better one and i still have the problem. I can back the BCS all the way out and it will lower my boost but when i try to go over 10psi no matter how high i turn it up thats all i can get.

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If you were only getting 10psi on a BCS, then you've got a problem that's not the turbo controller. Check for a leaky wastegate/CBV if you've pressure checked all your pipes properly.

Possible that the wastegate screw is backed off too far?

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kib... when it was stock i didnt have a gauge but im guessing i was only getting about 6psi, the needle on the factory guage would only barely go into the white. Now with the MBC and the Boost gauge and the MBC turned all the way up im getting 10 at best.

how can i pressure check my pipes ? I must have a leak there .

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Do you have a boost guage or are you guessing at 10 lbs? Take the vac line off of the wastegate acuator and CAREFULLY see if it will boost over 10 lbs. If not, the problem aint your MBC.

Gary

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yep... thats how i have it hooked up. the top of the BCS to the wastegate and the bottom to the BOV.

I have my BCS turned all the way up and i have the wastegate arm turned all the way in tight and im still only boosting 10psi.

i have a boost gauge mounted on my pillar and it seems to be reading correctly. when im driving down the highway and let off the pedal im showing about 20 inches of vac. and when i mash on it the best im getting is 10 punds of boost... i must have a boost leak i guess... ??? :huh:

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yep... thats how i have it hooked up. the top of the BCS to the wastegate and the bottom to the BOV.

I have my BCS turned all the way up and i have the wastegate arm turned all the way in tight and im still only boosting 10psi.

i have a boost gauge mounted on my pillar and it seems to be reading correctly. when im driving down the highway and let off the pedal im showing about 20 inches of vac. and when i mash on it the best im getting is 10 punds of boost... i must have a boost leak i guess... ??? :huh:

after warmed up on the highway after 15 or minutes and you put it in park, whats the Vac. ? On the highway and I let off its around -24/25 of vac.

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after warm up its about 18in. or so. Here is a pic of the hose that connects to the turbo and the hardpipe. if you notice on the pic the hose is swollen im thinking that may be my boost leak. When i touch the swollen part of the hose it feels real soft, but i couldnt feel a tear or hole in the hose anywhere. I unhooked the vac hose from my MBC to the wastegate and drove the car and it still wont boost over 10psi.

Im gonna try and take it off tomorrow and look at it. what do u guys think? is it common for this hose to burst? this car has 200k on it.

000_2457.jpg

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000_2457.jpg

this is NOT a picture of "Stage zero is complete!

if you get the same 10PSI of boost with the MBC hooked up right & wrong, something is VERY wrong there?!

did you read the link to IPD's wastegate adjustment?

did you apply pressure to the wastegate to rule it out as a possible problem?

you could have a cracked turbo housing and/or a restricted exhaust

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russ.. as i stated earlier... i disconnected the hose going to the wastegate which should cause a high boost situation and im still only getting 10psi.

yep... i agree i have some more stage 0 work to do, i overlooked this problem. i truly thought the hoses and such for the turbo and intercooler where in good shape i just found the problem in the pic yesterday.

i read the link for adj. the wastegate and will do, but, with unhooking the wastegate and driving the car and it still not going over 10psi. then the problem is someplace else.

as far as a restricted exhaust im not sure how to check that. the car pulls very very strong up to 10psi. it will spin the tires. im going to take that hose off the turbo and see if i have a leak there. if not, im gonna have to replace it anyways its about to tear soon..

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