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Crazy vaccuum issue

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kleenf4i

Proven Member
259
0
Oct 30, 2012
tampa, Florida
95 Gst.
Ok so today I went to clean up the vaccuum lines. I was doing this by following diagrams. Apparently the previous owner used to have a manual boost controller but took it out. He also deleted alot of the solonoids, which are not needed with the m.b.c.

So now when I got done with re routing the vaccuum lines, it horriably boost.it takes until about 6k to hit 10 psi. it used to hit 12psi at about 4500 rpm.

SO here how I ran the vaccuum lines
for the greddy type s bov: top port vaccuum is ran directly to the intake manifold. the bottom port is ran to a port on the top of the intake next to the throttlebody(where theres 3 ports)

the actuator wategate vaccuum hose of the 16g: is ran on a port going into the intercooler charge side about a foot away from the turbo j-pipe.

is there something im missing here? i know theres nothing wrong with boost leaks or such as those things.

any help is appreciated. I couldnt find a diagram that fit my set-up.
 
Ok something I'm starting to wonder about. When I got the car he had the wastegate arm almost fully extended.which in turn would leave the waste gate open and not build boost..but it did build boost...that's why at all the same time I adjusted the wastegate and re did the vacuum like it should have been, but now I lost boost. ?? How does this even happen? The only reason I can think of that it made boost before is because the wastegate essentially had no boost going to it to actuate and open further.

What bov are you running? Sounds almost like your bov is opening too soon.

Greddy type S. It's the real one, not eBay came with the intercooler
 
Is it recirculated? Was it leaking under a boost leak test?

How were the lines running exactly? I assume wastegate -> T, BOV -> T, and T-> manifold? You said there was as ball and spring in the T?
 
Is it recirculated? Was it leaking under a boost leak test?

How were the lines running exactly? I assume wastegate -> T, BOV -> T, and T-> manifold? You said there was as ball and spring in the T?

Recirculated and yes that was the set up..and yes the waste gate hose had a check spring/ball in it, which Is not needed unless im running a M.B.C. the only advantage otherwise would be if there was an issue with the wastegate opening prematurely.

Ok,I did some research on what the check valve T purpose was. Upon research,I found that it will make the boost come on allot faster due to the wastegate not getting boost until the check valve pressurized first. So I found the little ball bearing and hooked it back up as before and it's allot better, but still not the same..in first gear I don't hit 14psi until about 5,500 rpm.then in second gear everything is as it should be.back up to 14 psi and pulling hard. This I achieved by UN hooking the waste gate arm and tying the waste gate shut. Yes I know about surge and all of that, but it does not surge at all.I think I'm just going to get a mbc and hook it up and see what the deal then it's..this thing is becoming ridiculous.
 
That being the case, it sounds like a failing waste gate actuator spring. Maybe you just need a new actuator. If it is shot, it'd cause a bunch of those problems, and with no pressure on it, the turbo would act better. You should vacuum test the actuator and see if it holds any pressure.
 
I will do that test in the morning and report back.

ok the actuator is fine. Inspecting it further, the actuator arm is at such an angle its scrapping on diaphram housing when it pushes out and in. So what I have done for now is unhook the arm and banded the wastegate shut. now I have boost again. And I can hear the turbo spool again.so now my question is, I have now noticed my BOV is really loud now also, not that im complaining, but what would cause this? its never been this loud. Thanks for everyones help

one last question. im thinking of going back to the t-25 to hit better spool times. Starting to sppol at 3500rmp kinda seems crazy unless i upgrade fuel and all. Just seems as a very late powerband with the 16g. Any thoughts?
 
It's loud because you actually have boost pressure in the intake piping now. They are pretty loud normally... you'll hear it even with the recirculated BPV's. The "diaphram housing" is what I suspect is broken. If you banded it shut and now it's working better, either that part is broken or mounted in such a way that the arm would keep the waste gate from closing. I also suspect you might have an exhaust leak before the turbo... that turbo should be ready to produce instant pressure at about 3000 rpm. My 18g is spooled and will immediately hit 20 psi if you step on it at 3200, so you've still got another issue somewhere between the discharge of the turbo compressor and the inlet of the turbine housing... possibly a big crack in the waste gate side of the turbine housing.

I wouldn't go back to the T-25. It's going to act just as poorly if you don't find out what is going on with the set up you have now. Plus, it doesn't spool up so much sooner as to make it any more fun or responsive than a 16g.
 
It's loud because you actually have boost pressure in the intake piping now. They are pretty loud normally... you'll hear it even with the recirculated BPV's. The "diaphram housing" is what I suspect is broken. If you banded it shut and now it's working better, either that part is broken or mounted in such a way that the arm would keep the waste gate from closing. I also suspect you might have an exhaust leak before the turbo... that turbo should be ready to produce instant pressure at about 3000 rpm. My 18g is spooled and will immediately hit 20 psi if you step on it at 3200, so you've still got another issue somewhere between the discharge of the turbo compressor and the inlet of the turbine housing... possibly a big crack in the waste gate side of the turbine housing.

This. If you keep the wastegate flapper shut and now you have boost, you have a wastegate actuator problem.

To check for exhaust leaks, put a little seat foam in a vacuum line with the engine running, it'll smoke out wherever it's leaking. That thing should spool much quicker.
 
alright cool Ill keep the 16g. im having such an issue coming up with the stupid boost leak. I think next im going to straigt pipe the turbo from the j-pipe to the throttlebody just to do 1 test run and see if that makes a difference. right now first gear hardly spools at all until about 4k then second gear is fine. Man, i hope I can figure this thing out. also there doesnt seem to be any exhause leaks from the mani, or the turbo mount. However like you are saying theres defiantly something wrong still. In my blt I never tested from the bov. only the intercooler, turbo and charge pipe. Im going to pull the bov off and see if that has a leak.

took it apart and it has 2 springs in it. is this normal?
diaphram and everything is normal.
 
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some say only use top nipple. some say use both ( bottom and top) the bottom one is only for quick release action. but it seems to work alot better with using both.

also the intake pipe clamp was super loose. I tightened it and now i see 14 psi at 4800 rpm. is this right? it still seems really really slow spooling. No exhaust leaks at all either.Man this is driving me nuts :banghead:

I also noticed that unless I floor the pedal it will never make boost even in 1/2 throttle it wont . 3/4 throttle it will make about 8psi. but holding 1/2 throttle steady will never produce boost no matter what rpm. im starting to thing something is messed up between the turbine and compressor wheel.

ok so an update. the turbo will NOT boost past 14psi with the wastegate shut. Im starting to think that theres something wrong internally with the torbo.
 
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Take off the intake to the turbo, stick your fingers in it, and see if the shaft moves in and out... That sounds dirty... ROFL

If it does, the wheels have hit the housings and it will need to be rebuilt. JusMX141 (Justin Whitesell) on here does excellent work. He built my turbo and its real nice and was a very good price. There are also a few other guys on here that rebuild turbos, but I have no experience with them, so I can't comment on them.
 
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Take off the intake to the turbo, stick your fingers in it, and see if the shaft moves in and out... That sounds dirty... ROFL

QUOTE]

I made sure to lube up before I attempted this. LOL j/j. no shaft play at ALL. I found the problem. I know Im going to get an I told you so. But anyway when I did my blt, i did it wrong in the intercooler. I was desperate to see why it wouldnt boost with the wastegate fully closed. So, I bypassed the intercooler and wallah. hitting 5psi at 3200rpm and 16 at 4900rpm. so I looked ata the back side of the intercooler and theres a huge gash on the bottom row( like the P.O. hit a parking block) He then turned the intercooler around so that it would "appear" undamaged. So now i have to find someone to weld it up or buy a new one:banghead:. I know its not really safe to run without an intercooler, but is there any safe psi i can run until I get a new one or have this fixed?
thanks to everyone for your help. at least I learned a whole LOT.
 
At least you found it. Remove it and hit some welding shops up to see if they can't just weld it closed. Otherwise you can attempt some JB weld/water weld and hope for the best. If it's a small hole a fix may be to get some really good sealant and thread a damn bolt through it. LOL.

Otherwise, front mount are decently cheap and you may be able to just buy another one. Check the classifieds on here or dsm/evo owners parts trader on facebook.
 
At least you found it. Remove it and hit some welding shops up to see if they can't just weld it closed. Otherwise you can attempt some JB weld/water weld and hope for the best. If it's a small hole a fix may be to get some really good sealant and thread a damn bolt through it. LOL.

Otherwise, front mount are decently cheap and you may be able to just buy another one. Check the classifieds on here or dsm/evo owners parts trader on facebook.

thanks.. yeah ill have to leak test it and havce a shop weld it. im not a fan of jb weld when it comes to boost. i mean 14psi is sure to blow jbweld off sooner than later. iim hoping to just get it fixed. if i spend 40$ then i save a 500$ intercooler.
 
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