Underboosting?

[Gleshlich]

Hey all, new to the forum. Been lurking for ages but first time making a post.

I own a Legacy GTB Gen 3 with a V5 STi swap. (Running a VF23 turbo and the ECU from the V5).

Ever since I've owned the car it's only boosted 0.7 bar on max boost. Stock V5s are supposed to boost closer to 1.1?

I noticed it run really rich when I was transporting some furniture with the hatch tied down and open a tad. Smelt worse than a petrol station

What should my troubleshooting steps be?

Current "mods" are pod filter and blitz dd blow off valve (both of which were there when I bought the car).

[Jono24]

You are on wastegate pressure.

Check the ecu isn't in limp mode, check for cel codes and then do a full ecu reset.

Check you don't have a split intake pipe between the turbo and MAF, test a new MAF is also another option. After a full ecu reset it'll probably boost better until it finds the issue that initially caused it to go to limp mode.

[Rosssub]

Also if you didn't do the conversion yourself, the boost solenoid might not be plumed up correctly or could be missing the 0.9mm restrictor pill. Both will cause WGSP.

Or if it's just the turbo and ECU that's been changed, not the long block. It could be Staying in limp mode because of the different compression ratios between the GTB and STI causing it to always knock.

Edited April 16, 2016 by Rosssub

[Gleshlich]

Theres no CEL. Should I go get it scanned first, find out what the shortblock and ECU are and join the dots from there?

[Rosssub]

You can check CEL codes manually by connecting two black plugs under the dash, then turning the ignition on. Any old stored codes will come up too. Check the section in here on manually reading ECU codes:

http://www.scoobypedia.co.uk/index.php/Knowledge/ReadingECUCodes

- What model is your Legacy exactly, BH5A/BH5B/BH5C? Code plate is on the passenger strut tower.

- What colour is your intake manifold?

- Is it running a single coil pack/leads?

- What are the codes on the cylinder heads? Pic's/Codes in here:

http://clubsub.org.nz/forum/showthread.php?41847-EJ205-EJ207-EJ208-Short-Block-Identification

Edited April 16, 2016 by Rosssub

[Gleshlich]

It's a BH5A5CD according to the plate. Intake manifold is a crimson red colour.

Not sure about the heads. Will have to check when I'm back home on Monday.

[Rosssub]

Sweet it's a BH5A or Rev A. The ECU is under the carpet in the front passenger foot well if you want to check that too.

Version 5/6 STI - J2

Version 5/6 WRX - A7/A8

Edited April 16, 2016 by Rosssub

[Gleshlich]

Had a look at the car today and wasn't able to come up with any conclusions.

Checked and there was a restrictor pill in the hose between the wastegate and turbo

Checked the ECU and can confirm it is a J2. The passenger side head is a 007 but I wasn't able to see the one on the drivers side. I did not that the intake pipe is the one from a twin turbo which the previous owner blocked off with a bolt and a hose clamp... ghetto ik.

Went to have a look at the engine code but couldnt find it. I did see the number for it but I don't think that means anything apart from not matching what it's supposed to be from stock.

I went to go read the codes manually but after opening the panel, I saw a lot of wires with electrical tape and no green connectors. Connected what I thought was the ECU read connectors which only started the door chime noise for when you leave your keys in the ignition (guess that annoyed the last owner). I've posted photos of the current wiring mess. Not really sure where to go from here. Also saw a little red button next to the throttle pedal but wasn't hooked up to anything on the back. Maybe previously used as a killswitch or two stage boost controller?

I'm well and truly stumped

http://imgur.com/a/0T95u

Ignore the first picture.

UPDATE: I didn't look in the right place. Went and had another look and found the plugs. Got spat a code 23 (MAF?) and a Code 12. My starter has been cranking slowly but I'm not sure what the code 12 means. Is it new starter time too?

Edited April 18, 2016 by Gleshlich

[Gleshlich]

Could the Twin turbo intake pipe be screwing with the MAF signal? I'll be replacing the pipe with a singe turbo on regardless, just wondering if I should get a AFM while I'm at it

[Jono24]

I'm suspecting you have a twin turbo engine with a sti ecu. (As Ross alluded to above.)

The be5a is a 8.5:1 compression where the sti is 8:1. Look at the rear of the passenger side head and see if you have blocked/clamped oil or coolant lines.

The intake pipe job sounds rough, post some pics if you can.

[Rosssub]

The TT intake will only cause an issue if it's leaking.

Definitely need to sort the MAF CEL, but the starter signal can be tripped by cranking with a low battery. See if the CEL #12 comes back at all. To reset the ECU/clear codes disconnect the battery for a few minutes. Or connect the green and black connectors together and go for a slow drive till the CEL starts flashing for all clear.

With just the green test mode connectors together and the ignition on/engine off. The boost solenoid should start pulsing open/closed. Blast some carby cleaner through the solenoid while it's pulsing to clean it out. If it's blocked you'll get WGSP.

Also make sure the restrictor pill is on the turbo side of the T-piece, white dot:

[Gleshlich]

Had a look in the dark so not 100% confirmed here. No hoses seem to be blocked /clamped lines apart from the intake pipe.

I've taken some photos of the vacuum lines off the turbo. They lead off to something that doesn't look very boost solenoid. Of the three lines going into in, one if from intake pipe, one is intake manifold and one is from the t piece on the wastegate/turbo. The top right line goes to the intake. Top left goes to turbo and the bottom goes to intake manifold.

Might need an expert to come help me out

The clubsub photo uploader doesnt'really like me so I've had to upload to imgur.

Where should I be looking to confirm what the shortblock is from? Theres a number on the top that says 504759

http://imgur.com/a/mO5dj

[Rosssub]

The blocked pipe leading to the intake is the factory BOV recirculation pipe, so nothing to worry about.

Your turbo boost solenoid hoses should look like this:

Your heads are version 6 STI with the LHC007/RHC008 codes so chances are the shortblock matches. If you can get a look inside the bores through the plug holes the TT/STI piston crowns are very different.

Edited April 18, 2016 by Rosssub

[Rosssub]

Which loom plug was for the door chime?

The black painted heater coolant line that's in this pic, with an aftermarket 5/8" coolant hose fitted. Is only found on the V5/6 WRX/STI block. So there's another positive sign it's a V6 STI block.

Here's your head code pic:

[Gleshlich]

I found the chime black plugs directly under the steering wheel. It was sort of right in my face.

The diagnostic plugs were right up against the centre console side so I didn't see them at first.

What should I be looking for on the piston crowns?

I'll have a look at the boost solenoid 'wiring' tomorrow when I get light.

What colour AFM should I get? Same colour?

[Rosssub]

The blue hose in this pic goes to your fuel pressure regulator:

 Gleshlich said:

I found the chime black plugs directly under the steering wheel. It was sort of right in my face.

The diagnostic plugs were right up against the centre console side so I didn't see them at first.

What should I be looking for on the piston crowns?

I'll have a look at the boost solenoid 'wiring' tomorrow when I get light.

What colour AFM should I get? Same colour?

Cool thanks, might unplug my door/key chime tomorrow.

The AFM is an insert type. Version 5/6 WRX/STI and BE/BH rev A/B/C all use the same one, p/n 22794aa010.

There's pic's of the BE/BH TT pistons in here:

http://clubsub.org.nz/forum/showthread.php?42022-Stripping-EJ208-Short-Block-Separation

Then IIRC the version 5/6 STI pistons have a deep square recess in the crown. Like the STA pistons seen in here:

http://clubsub.org.nz/forum/showthread.php?43004-Rosssub-s-Single-Turbo-Conversion

Can see in your pics that your BBOD/TT solenoid box is still fitted. Unbolt it from the guard and the insides will look a bit like this. The hose from the turbo t-piece runs to the side port on the solenoid. The top port on the solenoid bleeds back to the intake pipe:

Top - MAP sensor

Middle - boost solenoid

bottom - Pressure change solenoid

Edited April 18, 2016 by Rosssub

[Gleshlich]

Sweet will have a look in the morning.

Should I be removing the bbod and leave just the bcs or just leave it as is and Check the plumbing.

[Rosssub]

To remove the BBOD you would need to modify your loom. Also the other solenoid and MAP sensor are still needed too.

[Gleshlich]

The hoses in the BBOD were all connected up properly. Cleared ECU, no more AFM code but still running wastegate. Rechecked for codes and theres nothing there.

Im guessing boost solenoid? When in diagnostic mode I don't hear it clicking away. Reckon its buggered?

Checked the pistons and it all looks good. Couldnt really get a picture in there through the plug hole.

[Rosssub]

 Gleshlich said:

The hoses in the BBOD were all connected up properly. Cleared ECU, no more AFM code but still running wastegate. Rechecked for codes and theres nothing there.

Im guessing boost solenoid? When in diagnostic mode I don't hear it clicking away. Reckon its buggered?

The boost solenoid should pulse constantly in test mode (green plugs), should also hear the radiator fans switching on and off.

If the fans pulse but the boost solenoid does nothing in test mode, try blasting some carby cleaner through it in case it's just stuck. Could also check the loom plug for voltage, should make a test light flash. BBOD loom plug wiring diagram post #28 in here:

http://clubsub.org.nz/forum/showthread.php?40911-Inside-the-BBOD/page3

It's the ECV duty solenoid wiring, pink and black wires going to the 2 pin plug mounted to the front of the BBOD. The 3 pin plug is for the MAP sensor.

If it's still showing nothing at all then see if the primary boost solenoid inside the passengers guard near the battery is pulsing instead. If it is, then the conversion wiring hasn't been completed and you have a couple of ECU pins to swap.

[Gleshlich]

Turns out I wasn't using the test mode. Boost solenoid ticks sorta like an idle. Nothing from the other side. All the wiring looks correct as to what you described

[Rosssub]

Sweet, Still could be blocked though. Pump some carby cleaner through the solenoid.

[Gleshlich]

Sweet will have to get my hands on some carb cleaner. Only have degreaser available. If this doesn't work what's next?

[Rosssub]

Degreaser will work, just make sure you get all the fluid out of any vac lines before connecting things back up. Next could be checking the WG flapper action, by gripping the WG actuator rod with pliers to force the WG open. Then letting it slap shut.

[Gleshlich]

Sweet as. Just took the solenoid out and degreased the pipes and gave the whole thing a clean. Left it disconnected and letting it dry for the night. Left the battery terminal off and had to manually lock all the doors haha. Hopefully that does the trick.

Would I be wise to change the AFM even though the code hasn't popped up again? I did about 250kms of driving after the last reset