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PCV system issues, modified ea-82t


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Ok guys, I have the fresh hot engine dropped in the RX and it looks sweet as hell with all the stainless stuff everywhere and the big garrett turbo and external wastegate. I know it took me friggin FOREVER but it's there. I have also been turbocharging a Harley and an LT1 350 so give me a little break.

 

Here's the issue:

The engine starts right up and runs ok for about 5 seconds then it cuts out. I can keep it running with the throttle but it doesn't like it. My last ea82t did this when I messed with the PCV system, I guess there was a little leak there somewhere. Well, this engine has been replumbed a little bit. I put in a new PCV valve and I just T'ed it off to the cam covers and the inlet to the turbo. It seemed wrong when I did it but I went with it anyway.

Does anyone know what the most basic setup is that will still make the engine run good? Can I just slap on some breather filters and call it good? I would love to know.

 

Also, I am gearing up for the megasquirt and I'm wanting to get rid of a lot of the vacuum lines in there. Which ones must I keep for it to run with the stock ecm until I can get the MS going?

 

I noticed that someone has done a really nice write-up for the megasquirt on an 87 RX (just like mine), wire diagrams, field values, etc. I can't wait to do it myself!

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Ok guys, I have the fresh hot engine dropped in the RX and it looks sweet as hell with all the stainless stuff everywhere and the big garrett turbo and external wastegate. I know it took me friggin FOREVER but it's there. I have also been turbocharging a Harley and an LT1 350 so give me a little break.

 

Here's the issue:

The engine starts right up and runs ok for about 5 seconds then it cuts out. I can keep it running with the throttle but it doesn't like it. My last ea82t did this when I messed with the PCV system, I guess there was a little leak there somewhere. Well, this engine has been replumbed a little bit. I put in a new PCV valve and I just T'ed it off to the cam covers and the inlet to the turbo. It seemed wrong when I did it but I went with it anyway.

Does anyone know what the most basic setup is that will still make the engine run good? Can I just slap on some breather filters and call it good? I would love to know.

 

Also, I am gearing up for the megasquirt and I'm wanting to get rid of a lot of the vacuum lines in there. Which ones must I keep for it to run with the stock ecm until I can get the MS going?

 

I noticed that someone has done a really nice write-up for the megasquirt on an 87 RX (just like mine), wire diagrams, field values, etc. I can't wait to do it myself!

 

 

 

can't just t the lines from the valve covers to the pcv.. the drivers side needs to go to the pcv, pass side needs fresh air :) or vice versa.. been a little while since i build an ea82t..

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Ok guys, I have the fresh hot engine dropped in the RX and it looks sweet as hell with all the stainless stuff everywhere and the big garrett turbo and external wastegate. I know it took me friggin FOREVER but it's there. I have also been turbocharging a Harley and an LT1 350 so give me a little break.

 

Here's the issue:

The engine starts right up and runs ok for about 5 seconds then it cuts out. I can keep it running with the throttle but it doesn't like it. My last ea82t did this when I messed with the PCV system, I guess there was a little leak there somewhere. Well, this engine has been replumbed a little bit. I put in a new PCV valve and I just T'ed it off to the cam covers and the inlet to the turbo. It seemed wrong when I did it but I went with it anyway.

Does anyone know what the most basic setup is that will still make the engine run good? Can I just slap on some breather filters and call it good? I would love to know.

 

Also, I am gearing up for the megasquirt and I'm wanting to get rid of a lot of the vacuum lines in there. Which ones must I keep for it to run with the stock ecm until I can get the MS going?

 

I noticed that someone has done a really nice write-up for the megasquirt on an 87 RX (just like mine), wire diagrams, field values, etc. I can't wait to do it myself!

Boosted, you can just breather the cam covers, its not the best setup but wouldn't be any different than any other older motor. You CANNOT tee the air tube connection to atmosphere as it will screw the MAF signal. I have a catch can setup on mine that works good and didn't cost much. The idea to the stock setup, is that you draw fresh air across one head, through the crank case, and through the other head. It also keeps the PCV system "closed" to outside air not passing through the MAF. The dual breather will vent pressure but doesn't do as well getting fresh air into the motor (helps with decreasing oil contamination and engine acidity).

 

The stock ECM really doesn't need any of the vac lines to run but you'll lose egr, evap, function if you get rid of them. Of course don't get rid of any FPR or 4wd lines.

 

I would get the MS on before monkeying with the stock stuff. Its so much more user friendly. I have a MS1 MsNs'e v2.2 on my 86. The DIYautotune.com write up is right on for your 87. Eventually, my egr and stuff will get function back on the auxillary outputs. I haven't really tuned mine in (still fighting the rear axles out for months so I can get the right rear in there).

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BB

you say

" I put in a new PCV valve"

 

Was this an OEM or aftermarket?

 

If OEM please excuse this question as...

Many times mentioned - an aftermarket PCV valve

is not the way to go on these cars.

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Ok, cool.

So I can just remove one 'T' and keep the passenger head venting to the turbo and the driver side head as well as the center vent for the cranckcase connected to the PCV valve. ?

 

I got the new valve at Autozone.

 

I deleted the EGR, I hope it doesn't screw things up too much.

 

I'll hook up the PCV system like I mentioned above and I'll let you guys know how she does.

 

Oh, the dimes did the trick in the HLA bores, there is no valvetrain noise to speak of, at least not for the few seconds that the engine runs. I can't wait to see how this setup performs.

 

***stage 3 Delta ground cams, light port job, 2" stainless header with collector, T3 turbo with large .60 compressor and .48 exhaust, 2.5" stainless downpipe, Audi external wastegate with separate 1.25" stainless downpipe, K&N filter, BOV, 5th injector.

I built a large water-to-air intercooler and it didn't fit! Damn! The new plan is to built an even bigger one that will mount to the passenger floorboard. Bonneville style baby! Bring on the dry ice! I'll slide the passenger seat back a ways since I don't have back seats anyway.

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The stock PCV system goes like this:

P/S Valve Cover to the port at the bottom of the intake boot (before the turbo).

D/S Valve Cover, Crankcase Breather and PCV valve connected together, then in to the other port on the intake boot.

 

That's how it is supposed to be hooked up. Make sure there is no openings from the crankcase to the outside air. Loose things like Oil Cap and Oil Dipstick can cause running problems with this setup, because with in opening on the crankcase, it would allow unmetered air to enter the intake.

 

If you remove it from the intake boot, plug the holes in the intake boot, and then connect the valve covers and crankcase breather all into a breather filter. Then plug the PCV valve.

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The stock PCV system goes like this:

P/S Valve Cover to the port at the bottom of the intake boot (before the turbo).

D/S Valve Cover, Crankcase Breather and PCV valve connected together, then in to the other port on the intake boot.

 

That's how it is supposed to be hooked up. Make sure there is no openings from the crankcase to the outside air. Loose things like Oil Cap and Oil Dipstick can cause running problems with this setup, because with in opening on the crankcase, it would allow unmetered air to enter the intake.

 

If you remove it from the intake boot, plug the holes in the intake boot, and then connect the valve covers and crankcase breather all into a breather filter. Then plug the PCV valve.

 

Sweet, I do have it all sealed from atmosphere though. Everything is connected to the turbo inlet between the turbo and MAF. It should all be metered the way it is but It doesn't like to run. There are no leaks, all new hose.

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Don't plug that line! If you cut there, run that to the intake. You do not want to prevent the driver's side valve cover from breathing on its own. That's what you'll do if you plug it there.

 

The way you have it set up is not correct, but will work. Ideally, separate the passenger side valve cover, and put that in a separate port into the intake boot.

 

Your problem is NOT your pcv system provided there are no leaks in it.

 

Below is what the CORRECT way should be:

PCV.gif

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The Autozone PCV valve is no doubt listed as the same one for the NA Sube.

As the pressure builds positive in the manifold the valve is not designed to handle this

"backward" as it may be pressure. This has been documented many times.

 

Plumb as you may, please remember this positive pressure in the crankcase can result in blown seals.

 

Sure sounds like a disconnected MAF or other major fault in this signal to the ECU.

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i just wanted to let u know my rx does the same thing but i can keep going with the throttle. i checked compression and 1 piston didnt have any psi. so its just a sugestion to check. it didnt throw any codes either.

 

I hope that's not the problem. I just built this thing. I'm pretty sure it's the PCV setup because I had the same symptoms with my last ea-82t after I messed with the PCV system.

 

The crappy thing is, mine looks like it's setup the same as the diagram in a couple posts back (except mine's turbocharged)

 

There was a hose coming off of the stock cast throttlebody inlet and I don't remember where that was supposed to go but I know I have run it many time with it plugged and it ran great. I can't imagine that any of the PCV plumbing should ever see boost pressure. I'll mess with it some more when the weather clears up...

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If your PCV system is hooked up like the diagram I posted, it is correct. Stop looking at it. No way will that cause problems unless there is a leak in it.

 

Your next step is to verify the MAF is plugged in, and to verify all other vacuum hoses are hooked up correctly. Follow the intake tubing and what not, and follow all the ports on the manifold and make sure nothing is open to the air.

 

Also, I'm assuming you have the AAV plumbed in correctly? (The thingy with two wires sticking on top of the T-Stat) It should have a hose that plumbs in after turbo, then another hose that goes to the throttle body after the throttle plate.

 

And you're correct in your assumption that the PCV system should never see boost pressure.

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  • 2 months later...

Well, I messed around with it briefly yesturday.

It seems to like o start but it doesn't stay running. Sorry, I have not checked the compression or the connection ofn the thermostat.

I did notice an unuasually large amount of crankcase vapors escaping from places like the dipstick tube. I can't imagine that the pistons/rings or cylinders are bad. But stranger things have happened. I didn't open up the block because the cylinders looked so good. I just did head work and put it all back together. There is only a few thousand miles on this engine (from what I'm told). I picked it up with a bad idler pully. The guy had just replaced the engine and he wasn't a mechanic, so I got a smoken deal on it.

 

I hope the block is goo because...are you ready for this?...I FINALLY BOUGHT THE MEGASQUIRT II !!! You heard me right. I'll start with the parameters listed on DIYautotune.com's 87 RX buildup. http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_subaru_rx_turbo.htm

 

I'm running a bigger turbo, bigger cams, better header and down pipe, no muffler, etc. It should scream. If not, I have an ej22 that I'll put in place of it and part the thing out to you greedy-subie-part-vultures.

 

Cross your fingers that the compression is good!

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There was a hose coming off of the stock cast throttlebody inlet and I don't remember where that was supposed to go but I know I have run it many time with it plugged and it ran great. I can't imagine that any of the PCV plumbing should ever see boost pressure.

 

That hose coming off of the cast piece is for the Auxillary Air Valve(AAV). It goes from the casting, to the valve on top of T-stat cover. Then out of that valve to throttle body. AAV will see boost. But the PCV should not as it is(should be) on the air intake side of the turbo, not the pressure output side of turbo.

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Well, I tested the compression and it was just over 90 psi in 3 cylinders and 60 in another. I didn't have the throttle open. I'm wondering if one of my HLA's are not pumped up enough to open the valve. The rings and cylinders were good when I put the heads on. I did a liquid leakdown on the cylinders and they looked great before I put the heads on. The valves were lapped and were sealing great. I can't imagine the head gaskets are toast. This engine only has about 2 minutes running time.

 

I plugged the line that comes off the the T-stat housing like it was before, no change.

 

I just need a sunny afternoon to finger out what the issue is.

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one word: WOT

 

you must have the throttle all the way open for a valid compression test, it DOES change the numbers.. 90 is a little low even for a turbo engine, so I would suspect all four figures. HOPEfully that will help line up that one cylinder thats off, too..

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BB:

 

Just plug your PCV port on the manifold, and run all the PCV ports/lines to a catch can with a breather filter on it. Thats what I have done.

 

As for the MS-II...there will be an ammendment soon, but the wiring has changed.

 

We are using BOTH injector drivers now...the 1-2 injectors on driver 1, and 3-4 injectors on the 2nd. Thats the way to go.

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