[Guest]

i want to do a boost test on my bpu supra. if i plug the pcv hose and put a pvc cap on where my air intake filter is located and install a tire valve, will it pressurize the entire system? will it also show a leak at bov? or do i need to test the left side, the right side, the bov, and the ic piping separately? went to Lowes and only found 3" pvc end cap? does not the intake manifold side require 2.5"?
what is the format for testing the entire system? also will it require water with soap sprayed on to find leaks? wha psi do i test at - 30lbs?

any feedback will be helpful?

thank carl

 

[93.5auto]

I would really appreciate someone answering CBDFLY's above question.

Thanks

 

[Steve Jarvis]

I would disconnect the hose going to the throttle body and cap it. I would then cap the hose going to the intercooler. Then you will pressurize the area from the turbos to the throttle body. This should tell you if you intercooler or piping is leaking. I would only test to about 20psi and see if it hold that pressure or if it slowly leaks down. If the pressure doesn't start dropping in the first 10 or 15 seconds then you probably don't have a intercooler or piping leak. Vacuum leaks will be a little harder, but typically a visual inspection will work.

Hope this helps, Steve

 

[Guest]

when i cap the throttle body side, do i need to plug the pcv? if i cap the hose going to the IC, how do i test from air intake to IC? i have done all the visual testing i can and replaced any hose in question, still no boost! do i just listen for leaks or spray a water/soap solution? can i remove the cap from the throttle body side reconnect hose and pressure from IC to entire intake system? which test will indicate a bad bov or pressure canister? when i go to Lowes the end caps are of hard plastic, is this used with a rubber connector and two clamps? not quite sure of how the set-up for testing for a boost leak goes? sounds like a three step(area) test. is there way to test the system completely hooked up with somekind of (test tube w/valve) to check system in its operating state? this is gettin to be a real drag! damn this boost leak!!! i will keep pluggin away at this..................

thanks steve

 

[Steve Jarvis]

I am not talking about pressurizing you intake manifold, so your PCV won't be an issue. Find something that fits in the hose going to the throttle body. Find something that fits in the hose going to the intercooler pipe in the inner fender. This is the one behind the airbox. Screw a vacuum fitting into one of the caps. You can then use a vacuum hose on the fitting to connect to your air supply. If you are getting no positive pressure than it is either in this area or you have bad turbo's. A vacuum hose would not be able to bleed off enough air.

Later, Steve

 

[Guest]

well, did the test. and nothing! i did as steve j. said, i capped off throttle body and pulled hose off hose to IC in fender, put pressure to it and it held 25lbs for over four minutes!!! then i did a pressure check on the intake manifold and the same thing, held pressure just fine. took off IC piping again,cleaned and tightened. took for a spin and still nothing over 15lbs!!!! what gives? i swear this is bullshit!!! i am a very methodical person and have checked everything i can think of and still nothing. if i do not find the problem soon.... get rid of the car and find another.

 

[Steve Jarvis]

Have you tried TTC?

Later, Steve

 

[Guest]

going to do it tonight! if nothing changes - this means what? if i get more than 15lbs - this means what?

thanks steve

 

[sleeper]

My problem was similar to yours when I was going through my boost leak phase. Could not boost past 1.0 kg/cm^2(~15.5 psi). I did the pressure test for the IC plumbing and everything was OK. I had a dp,intake,exhaust, and a Blitz DSBC. At BPU level minus the EBC, max boost is about 1.0kg/cm^2 which gave me a clue that the boost controller might be the culprit. Here is a trick I learned from one of our more experienced members. If you are BPU with a EBC, remove the cap from the bottom of the wastegate actuator. This will effectively keep the wastegate closed and give you maximum boost. Do this with extreme caution, go out on a WOT run and keep an eye on your boost gauge, you should only bring it to about 5200rpm, at this point you could be hitting 1.4kg/cm^2. This was my confirmation that the IC plumbing was OK. I eventually tracked down the problem with the electrical connectors on the Blitz solenoid and the controller. One of the pins broke loose from the body of the connector and never made contact. I was essentially running with the boost controller turned off, which gives you only about 1.0kg/cm^2 of boost. If you have a EBC check you electrical connections. Good Luck.