evodownunder101

Okay guys I purchased my Evo 8 used and when i got it this is what i found i been driving around with it the way it is for about 15 thousand miles. Well I guess what happened was a Manual Boost Control (MBC) was put on but than they took it off and I found the vac line were the Waist Gate is at zip tied to another hose but not connected and the Boost Solenoid only has one nipple on it, when it should have 2 I have a feeling it broke off b/c there is duct tape around the Boost Solenoid and where the intake hose is at its capped off. So what i would like to know is if this is bad?? Could this be a reason why i just started getting a "Service Engine Soon" would come on going about 70mhp?? Please if someone can help me thanks!!

PS: I know this photo is not a Evo but its a good diagram of what I am talking about. 1 photo is how the vac lines should be connected. 2 photo is how my vac lines are connected. Sorry for all the words.

Photo 3: Can you tell me if its broken? and if I keep this solenoid can it be used with a MBC??
Photo 4: Should a vac line be connected?? or should it be capped off??

Thanks everyone for helping me!!!

Piro Fyre

iTrader: (23)

Is the code reading "EGR something inefficient" or something alone that line? I had this problem too and had to replace the boost solenoid. I went to the dealership and they called it an "Valve, emission solenoid". Don't know if my code went away but just something you should know.

Also, I would STOP boosting if I was you. I was overboosting to 30psi when my lines weren't connected to anything.
You should have to diagram under your hood. Hook it all back up the way you see it.


I would suggest just getting another MBC instead of the boost solenoid. As for the boost solenoid, just cap it off and never use it.

evodownunder101

Wow damn I hope I didn't mess anything up when I would hit boost. Thanks Piro for all your help. Do you remember how much that peace cost you?? Can someone tell me what are the consequences of over boosting?? What could happen.

R0b

sounds like there was a boost controller put on previously.

if the last owner took it off, then you will need the 2 hoses as per diagram to control your boost

if the boost controller is still in, then boost is controlled via that so the factory solenoid isnt needed.

Piro Fyre

iTrader: (23)

That little piece costed me $70!!! Was a waste because my boost was then stuck at 12psi and stock boost is 20psi. Now, I have an MBC and since they called it an emission valve, I just left it plugged into the harness and capped off the vacuum holes. Just hoping when I clear my codes, I don't get the "EGR flow inefficient" again.

Consequences of overboosting can result in things blowing up like a piston head or other things. Without a tune, a lot of things can go wrong and they aren't small consequences. I just got lucky that nothing happened to me when I was overboosting.

evodownunder101

That's pricey for a little piece. Okay, thanks everyone!!! I will be going with a Manual Boost Control, and fixing the lines up asap. One more question if there is any damage done to my engine such as blown piston head or anything else would I notice it right away?? The reason I am asking is b/c just recently I noticed odd noise coming from the turbo when it would spool. Sounds like something grinding or some what of a supercharger. It would only do it once in a while. Thanks!!!

evodownunder101

UPDATED!!! with pics thanks!!

evodownunder101

Can anybody help me thanks!!!