Boost leak test, running like crap

[BoosteDsm1993]

I built a boost leak tester the other day and decided to test the system for leaks last night. Once I got to 20 psi and removed the compressor, it would go back to 0 in about 5-10 seconds. Using soapy water, I found a leak at the BISS screw, as well as the vacuum lines running to the throttle body (anybody know where I can find lines equivalent to these, as they are cracked?). Also, there was a massive hissing noise coming from what sounded like the throttle body, but I couldn't pinpoint it. Are there seals that could be leaking in the TB that I need to replace? If somebody could give me the part numbers, that'd be great. Hopefully the local dealer has the parts in stock. Also, After I did the test, the car doesn't run good, almost like it has a misfire. I'm going to take a shot in the dark here and say that because I pressurized the system with 20psi (Car only sees 8psi on the evo 3 right now because of a lack of fuel system) I made the leaks that much worse, and it's causing the symptoms I'm having?

 

[ChiTownHussla]

Boost leak test wont make it run worse....probably just a coincidence. And the TB has a gasket and seals. your vacuum lines can be had at any auto parts store. Biss screw for idle adjustment can be found on STM website. How about your fuel injector seals? were those ok?

 

[BogusSVO]

Read this thread..

http://www.dsmtuners.com/forums/newbie-forum/451983-boost-leak-test-results-questions.html

Some of the part numbers you need is posted in it.

If you run 8 psi and you tested at 20 psi, what was seald to hold 10-12 psi is now leaking.

 

[BoosteDsm1993]

Alright, I think I'm just going to head down to mitsu and buy the injector seals, the biss screw/oring as well as the throttle body gaskets. Although, it sounded like the hissing sound was coming from the inside of the TB, although I'm not positive. I'll replace the aforementioned items, and re-test to see where I'm at. Thanks for the help, I'll check back when this is done (sometime early next week).

 

[BoosteDsm1993]

Just an update guys. As usual, I didn't have the time over the past week or so to head down to my local mitsu dealer, I will do that tomorrow. However, I did do a compression test (150-150-152-150) which really surprised me. Motor is doing good, for once something is going right! Car has 125k on it now, and was all stock until I got ahold of hit (surprisingly). Replaced the vacuum lines, and noticed that the positive terminal was really loose. Doing this helped the problem ever so slightly, but it still feels like it has a miss. Idle is low, almost sounds like it has a set of 272's in it haha. But anyways, I'll check back tomorrow with updates.

 

[turbolover10]

I would run another boost leak test at 10 psi after you replace the seals and gaskets. Go through all the clamps and couplers with soapy water and really take your time. Whens the last time you changed the plugs and wires? Fuel filter, timing components? If your unsure of the last time these things where replaced it would be wise to tune everything up when funds allow it.

 

[BoosteDsm1993]

I would run another boost leak test at 10 psi after you replace the seals and gaskets. Go through all the clamps and couplers with soapy water and really take your time. Whens the last time you changed the plugs and wires? Fuel filter, timing components? If your unsure of the last time these things where replaced it would be wise to tune everything up when funds allow it.

As I've said before, this car is not a daily use vehicle right now, just when I don't feel like cranking up my car to drive short distances (especially with forged pistons), it makes me cringe. The plugs just got changed around 1000 miles ago, and the wires are due for replacement. I have a fuel filter sitting in my room, I'm just waiting until I get the link, so I can install the pump/filter/injectors all in one shot. The timing components are going to be replaced before the car starts getting driven every day again. That, and it is due for pads/rotors/better cooling system to handle the heat of Arizona, as well as an oil cooler for the trans. It's a slow process, but I have a bonus coming up at work and I should be able to get almost of of this stuff done at the same time. Thanks for the input. Oh, Mitsubishi didn't have any of the components I needed, So I'm just going to order online.