Razerx

TT,

thanks i came so some of the same conclusions. i need to get a compression test done. Since i dont' have the equipement i have to find a shop to test it.

i have already done what you suggested and i am pressurizing at the elbow of the TB, and it holds no pressure. all the manifold seals appear to work at least those i can see and get soapy water on.

So if the engine is not blown. Then i will buld the blocker plate for the exhaust and one for the top of the LIM. This way i can see determine if is in the manifolds or something else since i can now see everything.

Background 2 months ago i pulled off everything, and tested every soliniod and pressure tested all the value lines on the rats nest. i found a slit seal on the primary rail where it plugs into the housing, so i thought i was good after i replaced it. But... i still seem to have a few issues and i am hoping to have Steve Kan tune my car so i want to make sure it is fine. i had someone else drive it and they thought it was "lazy' in the 3-5k range but was great after that. i hear some boost noise so i started the project under the impression i had a leak, and at high RMPs i have so much air volume takes care of the leak.

I understand leak finding sequence.

Anyway unless there is a do it yourself compression check, yes i have a regular compession gauge i guess i have to wait to get that done.

Mahjik

iTrader: (1)

http://www.rotaryresurrection.com/3r...ion_check.html

Razerx

Thx for the info.

TitaniumTT

I wouldn't build a plate for the gasket between the UIM & LIM as that could be a potential leak. By swapping back & forth between blocked and unblocked you are throwing variables into the equation. I would leave that alone and test from the air filters to the throttle body elbow, and from the throttle body to the exhaust with that blocker plate in there.
-B

Razerx

LOL, i did that already not of it holds a pound. so i am moving to the next logical place. i am guessing LIM, vacuum line, ACV, which all buried with the UIM and TB so i can't even find them if they were.

s1mpsons

iTrader: (5)

I am using a bike pump and was also unable to add any pressure to the system using fighters garage pressure tester and cap on the two inlet pipes. I hadn't tried turning the motor before giving up. Any new thoughts on using this equipment?

arghx

iTrader: (3)

Dale is on the right track here.

Don't worry about rotating the engine. This isn't the same as a cooling system pressure test. You are just trying to figure out where the air is leaking. I have been doing these types of tests on single turbo Rx-7's and twin turbo 3000GT's for years.

Set the air compressor regulator to 0 psi. Hook the pressure tester up like you had it before--one inlet blocked off, the other pressurized. Slowly open up the regulator until you hear air flowing through the system. A bunch of air will leak out. That doesn't matter. If you've got enough leaks, you may have to turn the regulator up to 40 or 50psi to get 5psi to show up on the car's boost gauge, and the compressor will be cycling rapidly trying to keep up with the air flow.

But as Dale said, the point is to listen and feel for leaks (also spray soapy water), not to see how long the car will hold pressure. If you can't feel any air shooting out then you've probably done your job. If you are slowly ramping the regulator up, eventually the tester will pop off. That's fine.

What I like to do after an engine build is to place the assembled longblock on a stand, cap off exposed vacuum nipples, and pressurize the engine on the stand from the TB elbow. Then I can take care of all the major leaks before the engine goes in. Then I pressurize again with the engine in the car. In this way I'm guaranteed to have no leaks before the engine starts. I have caught leaky fuel rails, leaky blockoff plates, etc. And the car never "holds pressure." It doesn't have to. You're just trying to find air escaping.



here is a pic of me prepping a 2nd gen turbo motor for a pressure test out of the car. On the right is the brake booster fitting capped off, and there are other nipples I temporarily capped which are not pictured here. I put the pressure tester into that cheap blue pep boys coupler there on the TB. Then I pressurize from there, ramping up the air compressor as I previously described. I can also check for exhaust leaks on the exhaust manifold because of the air escaping out of the exhaust port. On that particular engine there was a leak at the secondary injector which I corrected before putting the engine into the car.

Razerx

Thanks good info.

i am going to go back and try it. I am pretty sure i have a leak(s) somewhere. i see a lot of lag on low end of the pressure, but more importantly i can hear the intake and blow off and it sounds like as i hold a constant throttle the pressure bleeding out.

i also now notice a sound like leaking pressure/exhause when the engine cold but goes away when it is warm. i did not not use to sound or perform like this. So not just a normal cold startup sequence.

I never thought of checking injector leaks that way but a brilliant idea! I had screwed up o-ring that got slit and that way of finding it would have saved a ton of anguish.

linnadawg

iTrader: (14)

Trying to help out any new people who may read this thread.

You need to pinch off the hoses at the charge relief and blow off valve.

I was able to get 15psi without rotating the engine. Around that pressure my dipstick would blow out. Air compressor around 100psi using a tire inflator.

I removed the rats nest to check for leaks better. Capped the whole upper manifold and the second nipple down on the lower manifold where there are four in a row. Then capped the open nipple on the pressure chamber. I left all the turbo lines connected.

You should not hear extremely loud PSHHHHhHHhHH noises. I had to tighten the testers down to get this to go away.

Soapy water found leaks on every intake gasket

tetsurobash

iTrader: (6)

+1