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Casem13

Proven Member
81
9
Apr 15, 2017
Olympia, Washington
My 97 gsx has minimal upgrades. I’ve installed hard intercooler piping, injen intake and have a 3” cat back. I finally installed an aftermarket boost gauge and here’s the issues I’m having. Even before the boost gauge install. My car stumbles on boost and when I get boost then I smell exhaust fumes after I left off the gas. And according to my boost gauge I’m only hitting 9psi at full boost. My oxygen sensor bank 1 is throwing a code as well. How do I check for boost leak? Do I just start up the car and spray the vacuum lines and intercooler piping down with soapy water or what? And what could be causing my issues?

Also to add. I did the waste gauge restricor removal for extra boost. I know stock boost is 12psi
 
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The 02 is why it's running like that man. Change it and report back.

But yes pressurize the system and then spray the pipes down with soapy water. Like I said though change that o2 sensor and that will fix it.
 
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How to:

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Couple of suggestions:
  • Complete the BLT when the car is warm.
  • Try the pressure test at different points you feel you may have a leak. It can help you narrow down your search.
    • After compressor housing.
    • After intercooler.
    • At TB inlet.
Don't rule out the possibility of the intake manifold gasket leaking (even underneath) in addition to the others mentioned. It can be tricky to track down leaks, but the soapy water method should do the trick.
 
The exhaust portion should not be under pressure during the test, so a bubble leak should not occur at the exhaust manifold. The exhaust is not a closed system (tail pipe).
 
You have a pre turbo exhaust leak. If you seafoam thru a vacuum line you'll see all of your exhaust leaks. Guarantee it's more than one broken stud leaking. Half the nuts are probably loose. Every DSM I've owned had several broken studs. If it's only one and you cant get to it without pulling the head you can get usually get away with double gaskets and a little copper rtv between them to hold you. Replace the studs and nuts.

Also not trying to be a dick but do another BLT. It is virtually impossible that you don't have several if your car is still mostly 20 year old stock rubber lines. Also physically check all the IC couplers and t clamps. I had a loose clamp on a lower pipe one time that created a leak so big I didn't even see/hear it with a BLT
 
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You have a pre turbo exhaust leak. If you seafoam thru a vacuum line you'll see all of your exhaust leaks. Guarantee it's more than one broken stud leaking. Half the nuts are probably loose. Every DSM I've owned had several broken studs. If it's only one and you cant get to it without pulling the head you can get usually get away with double gaskets and a little copper rtv between them to hold you. Replace the studs and nuts.

Also not trying to be a dick but do another BLT. It is virtually impossible that you don't have several if your car is still mostly 20 year old stock rubber lines. Also physically check all the IC couplers and t clamps. I had a loose clamp on a lower pipe one time that created a leak so big I didn't even see/hear it with a BLT
The ca
You have a pre turbo exhaust leak. If you seafoam thru a vacuum line you'll see all of your exhaust leaks. Guarantee it's more than one broken stud leaking. Half the nuts are probably loose. Every DSM I've owned had several broken studs. If it's only one and you cant get to it without pulling the head you can get usually get away with double gaskets and a little copper rtv between them to hold you. Replace the studs and nuts.

Also not trying to be a dick but do another BLT. It is virtually impossible that you don't have several if your car is still mostly 20 year old stock rubber lines. Also physically check all the IC couplers and t clamps. I had a loose clamp on a lower pipe one time that created a leak so big I didn't even see/hear it with a BLT


The car is old but I rebuilt the engine a year and a half ago and replaced all vacuum lines and hoses. And no broken studs at all. Just one missing nut on the exhaust manifold that I need to put on. All gaskets are brand new and torqued to spec.
 
OK well please fill out a profile. Buy a 5¢ nut. Are you sure you're smelling exhaust and not fuel? As I said exhaust leaks can easily be found with seafoam. A boost leak can make you run rich so you'll smell fuel.
And as I said I had a similar.problem after I put my motor in, after swapping a bunch of other parts turned out to only be a completely loose clamp on the lower pipe.
Personally my O2 sensors never work and it doesn't effect anything. My emissions drive cycle starts over everytime the key is off (as do many many 96-97 dsms, unfortunately only talons are exempt) so my O2s always read not ready.
 
Restrictor removal mod usually puts you at 15-18psi, if you have no boost leaks then that means you don't hit fuel cut at all (you haven't mentioned it at all so I'm just assuming) , the studder building boost could be bad spark plugs or maybe timings off. And are you absolutely sure the vacuum lines from the wastegate to the BCS are on the correct way?
 
Restrictor removal mod usually puts you at 15-18psi, if you have no boost leaks then that means you don't hit fuel cut at all (you haven't mentioned it at all so I'm just assuming) , the studder building boost could be bad spark plugs or maybe timings off. And are you absolutely sure the vacuum lines from the wastegate to the BCS are on the correct way?

I will check to make sure the vacuum lines for the wastegate are correct. I’m not fully sure if they are. I don’t have a diagram and I wasn’t the one who took the engine out when I rebuilt it. A shop took it out but wanted $5k to rebuild it and I told them to suck it.
 
Restrictor removal mod usually puts you at 15-18psi, if you have no boost leaks then that means you don't hit fuel cut at all (you haven't mentioned it at all so I'm just assuming) , the studder building boost could be bad spark plugs or maybe timings off. And are you absolutely sure the vacuum lines from the wastegate to the BCS are on the correct way?

The timing is good. I’ve checked it multiple times. And I haven’t checked the spark plugs since I rebuilt it. They are the plugs that were already in it when I got it. I inspected them for putting them in and they were fine. I’ve only put 5k miles on it since I rebuilt it
 
if my memory is right. the top nipple on the BCS goes to the intake tube and the bottom one tees off into both the waste gate actuator and boost source, as for the spark plugs. it's a cheap part to replace. get ngk bpr7es. gap to. 028
 
What I'm not sure is, why hasn't an actual BLT been performed? Not just spraying water on vacuum lines LOL..as stated in one of these posts, please pressure the intake tract to see if your leaking. If not move on from that to next test.

I had a similar issue and it turned to be extensive exhaust leaks PRE o2 (exhaust manifold gasket, turbo gasket, o2 housing gasket) causing the o2 sensor to freak out. I had hesitation, stumble and my manifold was glowing red from just normal crusing.
 
What I'm not sure is, why hasn't an actual BLT been performed? Not just spraying water on vacuum lines LOL..as stated in one of these posts, please pressure the intake tract to see if your leaking. If not move on from that to next test.

I had a similar issue and it turned to be extensive exhaust leaks PRE o2 (exhaust manifold gasket, turbo gasket, o2 housing gasket) causing the o2 sensor to freak out. I had hesitation, stumble and my manifold was glowing red from just normal crusing.

I don’t have access to an air compressor to put constant pressure on the system. That’s why I just start the car and let the normal load pressure be used to test for leaks. When I rebuilt the engine about a year and a half ago I replaced all gaskets on the exhaust manifold, manifold to turbo, turbo to O2 housing and everything. There are no leaks. The O2 sensor has been acting up for a while. Like I said earlier. The only exhaust leak is a tiny one from the far right of the exhaust manifold because I’m missing a nut there and need to buy a new one to tighten it down.
 
I don’t have access to an air compressor to put constant pressure on the system. That’s why I just start the car and let the normal load pressure be used to test for leaks. When I rebuilt the engine about a year and a half ago I replaced all gaskets on the exhaust manifold, manifold to turbo, turbo to O2 housing and everything. There are no leaks. The O2 sensor has been acting up for a while. Like I said earlier. The only exhaust leak is a tiny one from the far right of the exhaust manifold because I’m missing a nut there and need to buy a new one to tighten it down.

a bike pump will suffice. that's what I used when I started out. I put hand soap in a water bottle, filled it up. poked a hole in the cap with a pen or something, shook it and sprayed certain areas then pumped the heck out of the bike pump to see bubbles. not fun but it got the job done. or you can have a friend use the bike pump while you spray the soapy water. I usually moved the tester to different spot as well because well, bike pump, turbo, fmic inlet, throttle body elbow were the spots I moved the tester when I had to use a pump. Again it sucked but it got the test done.
 
I feel as a bike pump would not work well. How do you tell what your pressurizing it to? You need a compressor/borrow. How are you verifying that it's holding more than 5lbs? I run only 13 lbs but I pressurize my intake until at least 20.

The main leaks I see are the J pipe gasket, TB gaskets and the TB shaft seals as well as possible IM gasket with injector seals. The soapy water is a plus though! You might have to drive down to Vancouver Washington and use my compressor haha!
 
I feel as a bike pump would not work well. How do you tell what your pressurizing it to? You need a compressor/borrow. How are you verifying that it's holding more than 5lbs? I run only 13 lbs but I pressurize my intake until at least 20.

The main leaks I see are the J pipe gasket, TB gaskets and the TB shaft seals as well as possible IM gasket with injector seals. The soapy water is a plus though! You might have to drive down to Vancouver Washington and use my compressor haha!

My friend has a compressor so I can test it. I don’t have a j pipe since I’m running the factory t25 turbo. But I’ll update once I test it
 
Update: I ordered a new o2 sensor. Should be here this week. I did a boost leak test and found two small leaks on the intercooler piping and fixed those, but also found two huge leaks. One at the bov gasket and one at the intercooler to throttle body gasket. So I’m going to seal those this week
 
Update again: I noticed that the egr vacuum lines were backwards and when I switched them to the way they are supposed to. I actually lost more boost. I was now at 8lbs. I sealed the bov and throttle body gaskets and now I get about 9 1/2 lbs of boost. My o2 comes in tomorrow and I just installed a ported o2 housing with all new gaskets. But while looking at my engine I noticed black around two spots on my manifold to head gasket so I’m going to replace that as well. I was thinking my wastegate actuator might be bad but i checked it out and it seems fine. I’m putting some pictures up to show the flapper and inside of my turbo.
 

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I was thinking my wastegate actuator might be bad but i checked it out and it seems fine. I’m putting some pictures up to show the flapper and inside of my turbo.

It may interest you to know there is a way of testing the waste-gate actuator to ensure it is working properly aside from a visual inspection:

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It may interest you to know there is a way of testing the waste-gate actuator to ensure it is working properly aside from a visual inspection:

You must be logged in to view this image or video.

Yea I saw this video. When I checked the wastegate actuator I just kind of pull on it some to see that it wasn’t stuck. I don’t have a gauge like he does to test it
 
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