Here's where I think it's leaking. I couldn't check, but something feels loose when I tap my finger on it. Thanks to mil spec for the picture.

 

I had a suspicion about that UIPC to BOV connect. none of the OEM clamps hold there well and many of the t bolt replacements do not fit well..

Just took my tester out of the bottom of my tool chest. I used a ball valve connector from home depot to slowly crack the line pressure to the tester. Used a long metal 2pc valve stem on the plate at the turbo so i can get a pressure reading from an accurate gauge.

Then you are not going to believe this, but Napa used to sell plastic ashtrays bigger on top and smaller on bottom. $3 fit the flex pipe to the TB perfectly. thick plastic as well. I did get a large t bolt clamp to hold it as yes when i ramped it up it blew off fast. Flew right by my ear...finally cranked it up and like you found leaks all over.

Here is what i found plastic BOV leaked from all seams and past the diapraghm seal. UICP pipes leaked badly to the BOV. BOV leaked badly to the turbo inlet hose. TB coupler leaked ( rough spot on one side, badly installed...used heat gun to soften and fix. ) Turbo outlet pipe had leak from one screw. All the couplers leaked minorly even with t bolt clamps until manually adjusted under pressure. UICP coming up from the IC badly installed as well...same fix as the TB coupler,

I did mention to block off the vacuum hose at the BOV... Listen and then un clamp it , if you hear any extra leaks on unclamping, the diaphram is shot or the housing or gasket is leaking assuming the vacuum line is zip tied

Symptoms include slight drivability issues in/out of steady throttle bucking etc


Im lookin g forward to hearing that you can boost quickly and hold 21-17 psi after all your hard work..Great job man..

 

You will find out after fixing all the other issues you have found ad are fixing..

Put a straight rule on the Manifold at the TB to ensure flatness and cross check it several ways..that will leak under vacuum and boost.

I would ask Mil-Spec about the possible cause for the leak from the TB pic there.

The phenolic spacers .. are those from the manifold to the head? Not a fan at all of those. Most are not machined exactly flat and the gaskets may not seal well so leaks after the charge system.
Principle is ok, just not much to gain at all from it..

 

Thanks again for following along and helping me with this.

It's a Grimmspeed spacer, I'm hoping it was well made. I did a full delete on the EGR including plugging the head, so I'm hoping that the manifold will see some cooler temperatures. I figured I was there, I might as well.

I sent Aby an email. I'll share the comments.

If I can budget it, I may get some T-bolts next week to help with this.

Updates when I have them!

 

Okay, so what I did was pull the hose off and plug the hose. I was thinking that the BOV might start to open. Well, with the BOV nipple OPEN, boost was coming through. With the hose back on, no air coming through. You were saying to pull the hose and then cap off the nipple?

 

Dang... So I determined that the air was definitely coming from there. Removed TB. Removed screw:



That o-ring is shot.

Unfortunately, I lost one of the little half-moon pieces to the depths of my engine bay. Dangit!

 

No i mean pinch off the 3/8 "vacuum hose to the BOV..pinch on pich off use smooth jaw pliers or something

.So air comes out the nipple w/o hose. it really should not. it is sealed by the diaphragm in the bov canister. I am guseeing you cant heard the leak when the vacuum hose is back on.
OK that means the diaghragm is leaking . If the seal in the bov just lifts you will hear air going back to the turbo inlet thru the BOV as it starts to lift.
It can also mean the housing is leaking air past the diaphragm to the nipple. How many psi? My ix holds 23 easily w/o crushing so ...? Did you also say you found leaks on the ix BOV body as well at some point?

Well for now just get the t bolts and fix the major issues. Then you can either replace with new ix or synapse. Fixing what you have done will most def help the spool.

BTW I saw the pic you posted...that is ugly broke :-0 Maybe Aby has the part to fix and it will be cheap IIRC that is some sort of bimetallic spring for the water heater circuit to the TB to help keep it cleaner and provide a deicing function in winter

?maybe someone local as a junk TB that the bit is still ok they will let u have.

 

Well, if I'm not running the coolant lines to the throttle body, maybe it won't matter.

The o-ring was really shot. I RTV'd it temporarily. I put it all back together. That little piece there is part of a 2 piece ring that goes around the shaft right below the spring. Probably keeps it centered. I also chanced reusing my TB gasket. A little RTV, again. I'm generally not a fan, but my local dealership doesn't keep anything in stock.

So, I think my only leak is the BISS screw, now.

 

Well, it seems a little better. I think I'm getting boost before 4k, now, but not at 3200ish. At least not by my eye. I had another pound of boost from last time I set it, too. Creeping in 5th gear. I'll adjust the actuator rod when the car cools down. Probably just take it down a turn.

I need to fix my tool to hold better. It's not holding more than maybe 10psi without blowing apart. I'm sure there's something else leaking.

 

Boost will vary in different gears. Doing a boost test in 2nd will show 3600-3800 peak when going WOT at 2500 4 th or 5 th gear will peak faster 3200 most likely w/o much leaking. typically I set mine at safer road speeds on 2 nd or 3rd then tune the tables for less boost( less WGDC ) in 3-6 gears

Look for sparky's threads on setting th WGA properly and determining boost creep in this section. Very helpful.. He may respond if yu pm him as well.

I d o feel for you so many issues and bits broke...chin up though...once the car gets sorted it will be something to be proud and very fun to drive

respects,

Milburn

 

Napa and other partsplaces sells gasket material by the sheet or roll. get one of the older guys to dig in the catalog....Cut to size and use a rubber mallet to get the holes and indents properly marked...use razor or exacto knife or sharp box cutter to trim carefully. Gently roll against the curl to flatten. re-assemble and grin :-)

 

I did another boost leak test. Got my tester to hold, too. Yay! Pumped 15psi and held. Couldn't find any leaks. I'm really happy about that. Slapped it all back together. Feels like it's running great. So happy. I'll do a log as soon as I can.

Thanks again for all your help on this.

 

You are most welcome , sir. Is the boost full at 3300-3600 now? On to tuning. !!!

Meanwhile ...enjoy and spread the word how to really diagnose the Charge air system

GL

 

Just an update, the car is running really well! I re-gapped the plugs to .025 last night and it seems to run even better. I'm really happy with the car right now. I have some things to address, but that's for my other thread.

Thanks again for all the help. So nice to have the power come on early and consistently!

 

Well, I got a log done this morning. Got VD running and am left wondering what's going on... again.

I know VD isn't the end-all of dyno numbers, but it gives you a good visual on what's going on with the car. I only have one copy of a dyno from a stock VIII and it's getting peaq torque much sooner.

I'm guessing I still have an issue somewhere.