help! boost leak test results = bad

[canadian booster]

i hooked up the boost leak tester with gauge and used an air compressor to shoot in some air. after about 2 minutes the needle moved to about 1 or 2 pounds of pressure, i removed the air compressor and within 10 seconds, the needs dropped to 0 again.

i knew i had a leak, but i didn't think it was THAT bad *lol* how am i even going to test it? i need a bigger compressor? i've read a few FAQs on boost leaks, anyone have any suggestions where to begin? maybe just trace as much as i can and tighten stuff point by point along the whole path?

[A Paratroopers 300zx]

Do you still have all of your emission equipment installed? (Like EGR, PRVR, carbon canister, AIVs) If so, there are a mess of vacuum lines that can be very old and brittle and possibly cracked. Ummm in your efforts to trace the leak, I would just delete unnecessary stuff like the AIV's... They are useless and Nissan got rid of them in 1993 lol. Take a look at this guide: http://s95014253.onlinehome.us/63104/212983.html And also this one for deletes: http://s95014253.onlinehome.us/63104/197490.html

[canadian booster]

nothing is deleted that i know of, i haven't done any yet, and i don't think the prev. owner would have. I'll start there i guess.. my Fairlady is pretty fast, i can't wait to go for a drive with the boost leaks fixed *lol*

[canadian booster]

PRVR is gone now, time for AIVs

[canadian booster]

AIVs are deleted now. carbon canister is next if i can find a sneaky way of doing it without pulling the front fascia off

[A Paratroopers 300zx]

Haha good luck! You might be able to get at it with the inner fender splash guard removed.

[canadian booster]

my friend said to get a smoke machine and blast it into the air intake to find where the leak is... neat idea, now if i only had a smoke machine.. heh. maybe i can rent one

[CrazedZ32Owner]

most auto shops should have one... its soo much easier

[canadian booster]

wonder if i can rent it from them, i'll call around. otherwise maybe i can rent one from a place that has speakers and disco lights and stuff my car was in an accident, looks like it hit a fire hydrant or something on the front left side, i didn't find out until i got it home and took the front fascia off :P i bet the leak is at the intercooler on that side. i hope it's just a hose or clamp..

[canadian booster]

i think i found my boost leak, i have to compression test it tomorrow (i don't own a compressor, my friend has one though) with the boost leak tester plug still. an intercooler hose wasnt very tight, and one of my BOVs was loose enough i could have pulled it right out of the hose, it's tight now.

problem though, i went for a spin, and i'm not getting over 6.7 lbs boost, i'm hoping it's just that the engine wasn't warm enough yet (over 60 degrees C), i'm cleaning the temp sensor and reattaching it tonight. my ecu is still clear, no codes.

question though: a lot of talk with safety boost is around detonation, what does it feel like? would i be able to tell if i'm driving or is it silent? does it feel like jerky motions?

[CrazedZ32Owner]

if im not mistaken isnt the factory PSI 7?? and safety boost is like 3 PSI IIRC.... i might be wrong, do you have an aftermarket boost controller??

[canadian booster]

I've got a Blitz boost controller, it sounds pretty accurate although I've had it turned 'off' in a report mode only where it doesn't adjust the boost

I think factory boost is 9 or 10lbs

[CrazedZ32Owner]

just checked factory boost level is 9-9.5 PSI safety boost is 6....you should be able to hear it if the car is tripping the det. sensor....if all else fails youtube it

[BigTDogg (MA)]

If your BC is off, you'll run wastegate pressure, which is 7psi.

[canadian booster]

No way. Hahaha! For a year now I've been banging my head trying to see why I was stuck in safety boost

Good to know, thanks!

[BigTDogg (MA)]

No way. Hahaha! For a year now I've been banging my head trying to see why I was stuck in safety boost

Good to know, thanks!

You won't go into safety boost if either of the following is true:

1) You no longer have your factory boost solenoids, as they were eliminated when you installed the BC. You can install a BC WITH the factory solenoids to retain the safety boost function, but many do not for simplicity sake.

2) You don't have a code 34 (detonation sensor)