The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Register Log in
Please Support JNZ Tuning
Please Support ExtremePSI

Boost leak?

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

gofast63

gofast63

10+ Year Contributor
382
28
Apr 22, 2011
Manchester, Michigan
This is a weird issue I have. i used soap and water to find the leaks I had. My turbo likes to creep to 18psi-20psi, running 450cc, bucks at 5500 then sometimes 6000 at WOT, my wideband will go -- when it bucks. But even if I go 60-75% throttle to keep around to 10-12psi it will buck very little at 5500 rpm. It's always at that point. The head is completely rebuilt so is the engine.

Things I have done:
Boost leak test many time.LOL none I can find.ROFL
Cleaned and gapped plugs to .28 ( their new nkg )
Checked for exhaust leaks. I do have a leak coming out of the flapper from the turbo. Probably explains the creep. (Seafoam)
Adjusted the greedy type s. Also replace the o-ring cause it was leaking. Yes this bov is a peice of sh!t.
Bov is recirculated

Things to do next:
Oil pan gasket leaking pressure???
Fuel pressure. I'll be surprised if it's out of adjustment. I always have it at 43 psi
Leak down test....:cry:

What am I missing?
 
Sort by date Sort by votes
You are out of fuel and likely experiencing fuel cut. You should not be making pulls and running than higher than stock boost levels until you have larger injectors. You will only go so far with your SAFC (600-700cc range) until you will have a hard time compensating for fuel. 660cc injectors would be good for your needs at this time. It would also not hurt to check to see if you have the larger flapper on your turbo, or look into getting one. Boost creep is not uncommon on a 16g turbo.
 
Upvote0
I forgot to mention I'm not running a boost controller. I'm guessing it's time for a new wastegate...? I've only been driving the car to figure out the issues that I'm having. I do have a safc but haven't but missed with it in 4 years.LOL I just want to drive the car stock to break everything in for a while. It also shutters cursing 45 in fourth gear at about 15 pounds of vac.
 
Upvote0
2gmitsueclipse said:
You are out of fuel and likely experiencing fuel cut. You should not be making pulls and running than higher than stock boost levels until you have larger injectors. You will only go so far with your SAFC (600-700cc range) until you will have a hard time compensating for fuel. 660cc injectors would be good for your needs at this time. It would also not hurt to check to see if you have the larger flapper on your turbo, or look into getting one. Boost creep is not uncommon on a 16g turbo.
Click to expand...

I didn't know I had that option. I do have my flapper ported though.
 
Upvote0
If it was my car, I would throw the 550's back in with the 16g. I would rather tune a little bit with the 550's than risk going lean. The 550's are approximately 22% larger than the stock injectors to get a rough starting point. My 2g has link but my 1g is pretty basic so I have evo 560's and a safc2. With a wideband and a boost gauge you should be able to get it fairly close.
 
Upvote0
I took it for another test drive last night. Just cruising no WOT pulls. It likes to spit here and there cruising. Haven't done any more test yet, it's way to hot out.LOL
 
Upvote0
lasershark said:
If it was my car, I would throw the 550's back in with the 16g. I would rather tune a little bit with the 550's than risk going lean. The 550's are approximately 22% larger than the stock injectors to get a rough starting point. My 2g has link but my 1g is pretty basic so I have evo 560's and a safc2. With a wideband and a boost gauge you should be able to get it fairly close.
Click to expand...

I was thinking about putting them back in. But it spits while crusing. I cleaned the fuel injectors with air pressure and carb cleaner and they spray good. My wideband hasn't showed me going lean yet plus i feather the gas pedal so it doesn't over boost. But I have to kick the turbo on to stop it from spitting.
 
Last edited:
Upvote0
550cc would be good but pushing it. Previous talon had a small16G on 550s @ 18psi. No Fuel cut. (but was close to max injector cycle).

Go bigger in case you upgrade turbo later. Save an injector swap.
 
Upvote0
The 550cc took care of that issue. But she seems like she's missing before going into boost or even cursing. You guys think its because it needs a better tune? I have a rough tune on it from rre.
 
Upvote0
Is it always at same rpm range for the miss? Cruise same speed in third, fourth and fifth. Does it happen to all scenarios?

What about boost, you say just before boost.. What rpm is it missing, what rpm do you start building boost and what rpm is full boost?
 
Upvote0
Chuck98TSI said:
Is it always at same rpm range for the miss? Cruise same speed in third, fourth and fifth. Does it happen to all scenarios?

What about boost, you say just before boost.. What rpm is it missing, what rpm do you start building boost and what rpm is full boost?
Click to expand...
It's between -15 to -5 vac is when it does it. I have to go into boost so it stops. It does do it in all gears but its little less noticeable cursing in 5th.
 
Upvote0
My first guess is maybe the LO throttle settings on SAFC are too rich now with 550's? Jot down current settings and try to lean out a little for cruise. If doesn't fix, restore back.
Got wideband? Is it lean or rich during cruise and pre-boost.

Other thoughts:
At 18-20 psi, .28 might be too big a gap. Can anyone else confirm plug gap? I would try and reduce the plug gap to between .24 and .26
Ensure your MAF is clean. Is your MAF modified Removed honeycomb? Heard of that causing misfires.
Quadruple check boost leaks / vaccum leaks.
 
Upvote0
Man I can't tell you how many times I did a boost leak test.LOL i forgot to mention it does hit 16 on the wideband when it stumbles on the wideband. But it also did this when i had the 450s in. But the wideband was normal. I'll make a video and post it some time tomorrow. Also fuel filter,plugs,wires,sensors, tb rebuilt,all new gaskets
 
Upvote0
The plug gap should be fine at .028" so no need to change that. I would try to add some fuel in the area of the stumble and see what happens. (LO throttle settings)
 
Upvote0
I was able to take it for another ride. It does it has i get closer to a shifting point. or if I keep it forth gear going 40-45mph. It does it in fifth but you can barely tell its doing it. I also have a parasitic battery drain. Cause I started to do a compression test, my battery ended up getting weak after going for a cruse. My voltage is good running and crusing on my safc. Now that I think about it. It might be the voltage regulator in my alternator is probably going...? Also no lights where left on. The battery donest like to stay charged and its new.
 
Upvote0
Okay I figured it out. One of my intake valves isn't sealing on cylinder one. Everything was just machined. I bet I was dumb enough to actually accidentally put a old intake valve back in. Lol It had 22% loss and the others 0%.
 
Upvote0
You must log in or register to reply here.

Similar threads

  • Question
2G Boost leak
Replies
4
Views
500
DSMPT
DSMPT
b00zt3d spyd3r
  • Question
Boost leak?
Replies
9
Views
476
Neil Van
Neil Van
605jdm
  • Question
2G Boost leak
Replies
8
Views
477
605jdm
605jdm
4everboosted
  • Question
Boost leak
Replies
9
Views
1K
luv2rallye
luv2rallye
jdmfairladyz
  • Question
Boost leak
Replies
4
Views
441
Rikolas
Rikolas
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top