Boast leak tester not pressurizing??

[UNDISPUTEDDSM]

whatsup guys, well i 'm installing some cams, and a wideband this weekend....so i decided to read up on the boost leak tester.....i go ahead and make my tester, plug it in and start pressurizing.....yesterday i was able to pump about 80 psi (according to the gauge on the 5 gal tank) without the gauge not even moving.....today i was able to pump another 60 without nothing......while driving i can boost fine....18-20 psi...no problems, but yet i try pressurizing it with the tester, and nothing on the gauge??? any ideas guys??

MODS: b16g, fmic w/ 2.5 piping from JR, 650's, walboro 255 rewired, MBC and the link....

 

[oldman]

Do you mean you pumped 80psi worth of air and the boost gauge didn't move? Go by the boost gauge.

 

[LaN-]

i dont mean to be rude or anything but your installing cam's, a wideband and you have that good of a mod list but yet you dont know how or never have used a boost leak tester?

 

[kelvinb]

like said above, use your boost gauge in the car.

 

[Defiant]

i try pressurizing it with the tester, and nothing on the gauge??? any ideas guys??

You're not at TDC.

 

[SlowSpyder]

Assuming that your boost gauge is hooked up the intake manifold then you wont see pressure if you pressurize the intake/ic piping because the throttle plate is closed.

 

[oldman]

Assuming that your boost gauge is hooked up the intake manifold then you wont see pressure if you pressurize the intake/ic piping because the throttle plate is closed.

If this was true, how will your car run at idle?

To the original poster, move the tester to the TB elbow and focus in smaller areas first. Listen for hissing under the oil cap, in the tail pipe, and disable your mbc on your next attempt.

 

[UNDISPUTEDDSM]

i will be trying doing it in sections.... i just dont understand what i'm doing wrong, i've read throu vfaq and just about everything else, but i still can't get the gauge to move....my gauge isn't hooked up to the mani, its running of the fpr (which isn't extremely accurate to begin with) but it should move nonetheless....my stock boost gauge doesn't seem to move either and i have my mbc disabled....one thing i haven't done was putting it on TDC, i will try that as well, but to my understanding it shouldn't matter....but i could be wrong.....any more ideas guys??

 

[oldman]

i just dont understand what i'm doing wrong, i've read throu vfaq and just about everything else, but i still can't get the gauge to move....and i have my mbc disabled..any more ideas guys??

It could be a lot of things, not too unusually for the gauge not to move if this is your first leak test. You could have valve overlap, leaking pcv, EGR, valve seals or rings, reasons why to listen for hissing under the oil cap and tail pipe.

my gauge isn't hooked up to the mani, its running of the fpr (which isn't extremely accurate to begin with) but it should move nonetheless....

Nothing to do with subject at hand but make sure you tapped into the line between the manifold and fps, not the line between the fps and fpr. It should be hooked up to the manifold.

my stock boost gauge doesn't seem to move either

Your stock gauge doesn't meassure real pressure, it calculates pressure using sensor reading via the ecu so it will never move until the car is turned on.

one thing i haven't done was putting it on TDC, i will try that as well, but to my understanding it shouldn't matter

It will matter but TDC is the only place you don't want to be because any cylinder in TDC means the corresponding cylinder (1/4 and 2/3) is at TDC between exhaust and intake stroke which will result in valve overlap, both intake and exhaust valves are slightly open resulting in air rushing out of the tailpipe. 30* after TDC is a good place for a static pressure test.

 

[UNDISPUTEDDSM]

thanks for the help.....i will go ahead and try doing the test at about 30* after TDC once i get home....it shouln't matter if i do the test with the TB open or closed??? if tried both ways regardless, but i would like to know if the right way is with it closed or open

 

[oldman]

it shouln't matter if i do the test with the TB open or closed???

It will not matter at all, the throttle plate is not suppose to close completely at idle position.

 

[UNDISPUTEDDSM]

cool, thanks....keep an eye out i'll post if i have any luck later tonight....thanks for the help again..