Alpine951

I just started my car for the first time and pulled it out of my garage two days ago since last December. I have been doing suspension work and a few mnonths ago jumped on a k27/6 that became available, so I have been doing the turbo swap. While the intake manifold was off I ripped out the venturi and replaced all of the hoses except for two. Now my car is hesitating violently when I get on the boost and can't get near the 18 psi I run. its like someone tied a rope to the back of the car and all of sudden yanks on it. I want to try and pressurize the intake. I have seen some pics here where you can stick a pvc end cap into the end of the intercooler pipe coming off compressor outlet. How can I attach a tire valve to the cap so I can use my tire compressor to pump air into the system. Also does anyone know the size of the rubber pipe that attaches to the compressor outlet since this looks like the place to stick the cap in since I want to test after the turbo.

Ski

start your car and spray some starting fluid by each intake runner - if the idle changes, you have a leak there. You have the brake booster hose going to the intake with the check valve in it, the IAS going back to the intercooler pipe from the manifold?

Alpine951

Ski,

I would rather do the actual pressurization because I think some things might only leak under boost. Not sure what you mean by IAS. If you are referring the idle stabilizer valve (ISV) that goes from intake manifolsd to intercooler pipe that has the diverter valve. The brake booster hose goes to the intake manifold. I wasn't aware that there was a check valve in the intake manifold where the brake booster hose attaches.

hosrom_951

Either of on these would be the best way to pressurise the intake system:

http://www.arnnworx.com/boost_testing.htm


" i wasn't aware that there was a check valve in the intake manifold where the brake booster hose attaches." That check valve is for the climate control system, using vacuum to open/close the re-curculation flaps.

There is another check valve on the brake booster itself:

J Chen

Hos, good info.

Alpine, if you're already using an MAF, the fuel filter method will
work. For my set-up I use a pressure regulator which I bought
from a ahdware store cost about 10 bucks. It's got a build in gauge
& the nice thing about it is that you can regulate whatever pressure
you set it too. To me I think it's safer as you do not over pressurize
the intake. Besides pressured air will still leak through one of the
cylinders & with regulated air the pressure is consistant which will
not mislead you into thinking you've got a major leak while search
for them.

Alpine951

I still have the afm. I just called the local NAPA. They have a valve stem that is threaded and has a nut on the end of with an oring. I can drill a hole into a pvc endcap and stick the stem in and attach it with the nut and oring on the other side. The regulator is a good idea.

David Floyd

https://rennlist.com/forums/showthre...ght=valve+stem

J Chen

Alpine,
with the regulator, all you need is to go to your regular
tire stock or a gas station & use their compress air or
you can also use this to check for exhaust leaks too.
How, just simply set the pressure stick it in the tail
pipe. Of course you got to make some kind of seal.
My tail pipe has a 4 inch tip so all I did was to seal
the filter by using rubberize foam between the circumference
of the filter & the exhaust tip. No need to using high
pressure 10-15 psi will do. If theres leaks it'll show
with a spray of soapy water.

Alpine951

Thanks David.

theedge

I used a 3" PCV end cap that fit perfectly into the JBoot and pressurized everything that way.

toddk911

Leaf bower with rag as seal stuffed in the J boot

Mike Murcia

I use a compressor with the regulator set to 18psi. I block the intake of the intercooler with a pledge can like this:



This way you can clamp it down to get a good seal. I then pull off the vac tee that has one port goint to the intake banjo, one to the fuel dampner, and one to the CBV. With the intake port vac line attached to the Tee, I attach a spare boost gauge on one side and the air compressor's air gun to the other, like this one:



You can then pressurize the intake with the gun and watch for leaks on the boost gauge. Sorry I don't have pics of the whole setup handy, but I can get them if someone is interested. It doesn't really require anything special as long as you have a compressor and a blowgun (and a dust free house).

hosrom_951

Just a note, while the fuel filter trick does work (used it several times) but do bear in mind that there would be other components in the intake system that you would be pressurising that DONT see pressure in the first place.

Such as the Air-Oil-Seperator, the J-Boot itself, fuel purge system (which goes all the way back to the "nipple" connector, also known as the thermo-vacuum-switch) and any other vacuum connection(s) to the j-boot.

Alpine951

I have another question. I have not been able to find any piece of PVC that will fit in the jboot. I found some pieces that will fit in the throttle body boot and the rubber elbow coming off the turbo compressor outlet. If I put a cap with a valve stem on the rubber elbow coming off the compressor outlet will air leak out of the compressor outlet? I removed the idle stabilizer valve and plugged up the intake manifold and the jboot because the body of the isv was leaking. I wasn't able to get as much pressure hooking it up this way compared to when I hooked it up to the throttle body boot.

J Chen

Aaaaah nipples, I just love them. The feminine kind I mean.
Well the air oil & fuel purge can be plug off easily Hos.
No big deal.