2G Boost leak test

[jerrylarsen]

So I was trying to do a boost leak test, and I never got more than 2 psi. I could hear and feel it going out of the exhaust. I kept pressure up while turning the motor slowly by hand and never got anything. So bad valves? Or bad turbo? The car still builds and holds boost, just it doesn't have much. I'm steady at 7 psi.
So... What's going on with it? Any help would be so helpful guys.

Maybe egr is stuck open?

 

[97_4g63t]

Are you using an air compressor? Try pressuring up after the turbo.

 

[jerrylarsen]

Yeah I am, I'll try that tomorrow

 

[91-GS]

Should do a compression test as well, especially if boost leak test is not be successful next time.

 

[911gdsmboostin]

Out of the exhaust where? Tail pipe?

 

[luv2rallye]

You do know you can't test at TDC because both intake and exhaust valves are slightly open on 1 cylinder (valve overlap), right? Just in case that's what you're doing.
See: http://www.dsmtuners.com/threads/bo...th-boostpro-net-tester.169435/#post-152554139

 

[jerrylarsen]

Yes out of the tail pipe. I turned the motor by hand slowly two entire revolutions and never got more then 2 psi

 

[luv2rallye]

You're turning the motor while doing a boost leak test (BLT)?
No, no - a BLT should be done when motor is set to around 30* ATDC.
BLT how to: http://www.dsmtuners.com/threads/boost-leak-test-how-to-with-boostpro-net-tester.169435/

 

[jerrylarsen]

I know I know, I was turning it trying to find the proper place cause I assumed I was wrong because my boost wouldn't build. Where should my cams sit? Have a picture?

I tried with where I thought it would be and was wrong apparently

 

[luv2rallye]

Set the Crank (not cams) to approximately 30* ATDC. Then pressurize the turbo inlet.

 

[jerrylarsen]

I figured I'd have to pull the crank shaft pulley or something to get it correctly?

I don't think there's any markings on it, but I suppose it would help if I looked haha

 

[luv2rallye]

The crank pulley (aka harmonic balancer) has a mark (or notch) on it's outer circumference. The lower timing belt cover has a tab with 5* increment lines on it. See 1st and 8th pictures here: http://www.plymouthlaser.com/timin.htm. So turn the crank pulley to approximately 30* ATDC - the exact position is not critical, just get it in that area. [Note: You can also just barely see the tab if you sight down in front of the water pump pulley towards the crank pulley although it would be easier if the alt belt wasn't there. I'm assuming you have a 2g.]

 

[jerrylarsen]

Thanks for the replies,
I'll test it soon and let you know.

 

[luv2rallye]

If during BLT you still get air out exhaust, check if EGR is stuck open.

 

[jerrylarsen]

Is there an easy way to test the EGR?

 

[luv2rallye]

Pull it off and check if stuck open (air passes through both ports).

 

[luv2rallye]

I'm sorry. I previously told you that all intake valves are closed at 40*BTDC. I didn't know what I was thinking - obviously there is ALWAYS at least one intake valve open on one of the cylinders at any time. For a BLT you want to make sure BOTH intake and exhaust valves are not open at the same time in any cylinder (valve overlap). That is why crank must not be at TDC (30* ATDC recommended).

 

[jerrylarsen]

Okay, I blocked the egr off (no emissions anyways) did a blt and found ass tons of leaks, injector #1 was the worst, all around the throttle body at the boltls, a large copper colored flat head screw... What do I do for those

 

[luv2rallye]

Probably have to replace injector o-rings (aka insulators):
http://fuelinjectorclinic.com/index.php?route=product/category&path=252_257 OR
http://www.dsmtuners.com/threads/lower-injector-seals.388643/#post-152428118 OR
http://www.streettunedmotorsports.com/parts/oem_dsm_fuel_rail_spacers.htm OR
http://www.streettunedmotorsports.com/parts/oem_dsm_lower_injector_insulator_rings.htm.

New throttle body gaskets or put sealant on them.
Also check for throttle body shaft seal leaks (which are VERY common on dsms) while opening/closing throttle plate while doing BLT: http://www.machv.com/throtbodseal.html

Check if BISS o-ring leaking/missing.
Check valve cover gasket area for leaks.
Check BOV fitting for leaks.
Check all intake hose fittings for leaks.

 

[jerrylarsen]

Kk will do and post results

 

[Mauispyder]

I believe the flat copper colored screw is your BISS. It's in a hole in the throttle body. Before removing it slowly screw it in all the way counting half turns and write it down. Then unscrew it all the way. It will be stuck in the depression. Cover it with a rag and do a quick BLT. This will blow the BISS screw into the rag. The screw is usually reusable. Just get rid of the old oring and get a new one from your favorite hardware store. I used a little hi temp plumbers lubricant on the new oring. Now screw it back in all the way. Then back it off the same number of half turns that you previously wrote down. Next BLT I'll set the crank correctly first. Thanks luv2rallye.

 

[jerrylarsen]

Well I fixed the injector leaking, I can hear something leaking down lower though but it sounds like the transmission though haha. I couldn't look more because it started hailing, I got up to 20 psi in the intake, right as my boost leak tester blew off , changed it to t bolt clamps and will try tomorrow

 

[luv2rallye]

Well I fixed the injector leaking, I can hear something leaking down lower though

Don't forget to examine air hoses attached to turbo.