Installed MAFT, now boost creep

[JJ_Is_Edge]

1998 Mitsubishi Eclipse Spyder GST

Mods:
Ebay 16g (came with the car)
3" cat back exhaust
550cc fuel injectors
MAFT
Greddy RS Knock Off BOV (blow through)
Pod filter/metal intake pipe
Metal intercooler piping

Okay, so here is my scenario:

I installed the MAFT a few days ago and have been toying around with tuning for the larger injectors. I still have the boost control solenoid hooked up in the stock fashion, no MBC yet, it's on the way.

Before this install, I'd build boost to like 10-12psi. You could definitely feel the plateau in which no more boost was being built. Now, I build like 22psi by 4,500rpm. Nothing changed except setting up the BOV in blow through fashion and the MAFT of course. I've searched but I can't find anything relating to this problem with the MAFT specifically.

Sorry if this has been answered before but I can't find anything. Any ideas?

 

[Dsmkauai]

Did you setup the bov at idle properly? Also Make sure the wastegate isn't stuck closed. And all vac lines are on properly.

 

[JJ_Is_Edge]

I opened the BOV screw until I heard it leaking at idle then closed it about 1 turn. It doesn't flutter when I let off the throttle, although it does make a wistle sound sometimes.

I'll check the wastegate next but it would seem really strange if it failed the exact moment I installed the MAFT

All the vacuum lines are hooked up correctly.

Also, I didn't mention but I have a pretty large exhaust leak right at the flange after the cat. I'm getting a new downpipe this week and already have a new o2 sensor housing with a larger recirculation tube. Could the exhaust leak cause the problem?

 

[JJ_Is_Edge]

Sorry for the double post, but I noticed some new things. So the car has been predominately sitting the past few months, I've only really gotten a chance to look at it closely the last few weeks and it seem the previous owner has left me a lot of headaches. As far at this problem goes, upon further inspection, I've noticed 3 things that could be causing this.

1.) The BOV flange on the intercooler piping (CX Racing) and the actual BOV bolt holes don't line up perfectly. I thought that if I put some RTV on both flanges and the gasket it would seal but I've noticed a slight vacuum leak at idle. I plan on drilling those holes a little bit bigger to ensure an air tight seal ASAP.

However:

2.) My exhaust manifold has an ever so slight crack on the top. Obviously, I know that any pre turbo leak will cause problems. However, it seems odd that my boost climbs all the way until 30psi/when my car cuts fuel. Shouldn't it be the opposite? The car pulls very nicely and the turbo spools quickly.

3.) I noticed he had one stud that is like, halfway broken. The stud is there but it's hanging by a thread. Any attempts at tightening it will surely break it off. I don't think the gasket is leaking though. I was hoping to weld the manifold, and replace the o2 housing and downpipe first and then saving up for a new manifold. But should I just drive it easy, stay out of boost, and replace the stud, manifold, o2 housing, downpipe all in one go? I'd really like to avoid drilling out the stud and if only one is broken I'd hope I could get away with leaving it as is but I also don't want to replace everything only to take it apart again because the gasket didn't seal properly.




My main question is, if I'm leaking from the BOV flange (boost leak) and have a pre turbo exhaust leak, shouldn't my boost be almost non existent? Sorry for the noob questions. I'm pretty familiar with working on cars, but I never really worked on turbo engines and am still learning. I've read up on this site a lot but it seems like the problems I've noticed should be causing the exact opposite of my symptoms. Thanks in advance

 

[pauleyman]

Check those vacuum lines again. You almost have to have a cut or a line connected incorrectly. I am guessing you unhooked some stuff for install.

 

[JJ_Is_Edge]

Okay, I think I may have found the problem! I didn't realize that the original turbo had a vacuum port on it. The way I received the car, the vacuum lines were hooked up as such:


Top vacuum hose on the BCS going to the Intake Pipe
Bottom vacuum hose on the BCS going to the Wastegate accuator

However, there is a tee that he capped off, and a cap on the LICP. From what I understand, the Wastegate currently has no boost source. Am I supposed to put a vacuum line from the LICP nipple to the tee in the BCS to Wastegate port?

Again, I'm very sorry if this has all been answered. I keep searching but I can only find diagrams for the stock turbo or 16g with a MBC which I do not have yet. I saw this description in another thread but I want to double check it before I hook it up.

 

[lasershark]

This should help you out
http://www.dsmtuners.com/threads/taboo-speed-shop-vacuum-diagram-and-removal-for-1g-and-2g.198327/
And I'm referring to the images, there are stock routing pictures. Pay attention to those if you are trying to keep your bcs.

 

[JJ_Is_Edge]

That was what I found, but it looks like it only has pictures for the stock turbo with a vacuum port on the actual turbo. However, I hooked it up according to the directions on there (wastegate to boost source) and it is holding 15psi steady and working flawlessly. The person who installed the turbo before I had the car had the vacuum line with a T but hat the split part blocked off so I assumed nothing went there. Thank you so much everyone for the help, I'm stoked it's finally working as it should and it was something as small as a vacuum line!

 

[lasershark]

It's always the little things
Glad you got it figured out...