120 replies to this topic

[Barbbachello]

glad i went single haha

[Robbks]

QFT

glad i went single haha

 

Owning a TT made me purchase a H6.....

[Ordex]

Guys - this is much much more than I had ever hoped for!

I'm very glad to know the VF18/19 setup will work happily with the EJ20H, I really wasn't keen on having to swap back.

Going to get stuck into fixing the clutch this weekend, and time-depending hopefully get everything back on the car.

 

Rob: I will try implementing your first diagram to delete the secondary wastegate plumbing before going any further with the simplification process. If I actually get some boost then I'll take it further.

 

I also sent Mines an email today to find out what tuning has been done to the ECU

[Ordex]

Can someone confirm if the pill should be in line 1 or 2. Both the BBODs I have here have a pill in line 2 but I can't feel one in line 1.

[Jimbo]

Line 1. Always the line that goes to the IACV.

[Ordex]

ok - I'll swap the pill from line 2 to 1 - assuming it is the correct size pill.

 

Is line 2 with a restrictor pill how a B4 is setup? I think the spare BBOD I have is from a later TT as the MAP sensor socket is a different configuration.

[Robbks]

Forget the pills and all that junk,
delete the lot as per my last pic.

Even forget about the boost controller on the primary
connect a short piece of hose from the Primary Compressor outlet to the wastegate actuator.
it will run 7-8psi

If you've used a BBoD from a gen3 the MAP sensor will be wrong for the early ECU
the Early BG5 had a map sensor with a lower resolution than later models.
you need to keep the correct sensors for the existing ECU so it knows where and when to operate the secondary

[Ordex]

Update: I put everything back on the car on the weekend as per Rob's first diagram (only minor BBOD modification) and noticed maybe a slight boost increase, but nothing significant. Hard to tell as I'm still waiting for my boost gauge to arrive. I then disconnected and blocked the line between the primary compressor outlet/wastegate to boost controller to try running wastegate pressure. It certainly feels better, but still not amazing.

 

Lastly I did a check for error codes and got nothing, which I found surprising given the previous state of the system.

 

Rob: I've already decided to move straight to trying the hookup from your last diagram. And I'll keep the boost controller out of the picture as well. Good point about the MAP sensor - any idea how I can tell which of the two MAP sensors is the right one? Otherwise I'll just try with both.

 

Also which is the best point to plug in the boost gauge? Throttle body where I will remove line 10?

[Robbks]

the MAP sensors will have a part# on them.
but best to go with the one that came with the car.

Boost gauge should go as close to the intake manifold as possible
my Legacy had a spare nipple on the Drivers side rear of the manifold

But you will probably end up with a spare on the front of the manifold where the Factory boost control and ECV plumbing is removed from.

[Ordex]

The part number on PartSouq for the MAP sensor on a <=96 GT is 22012AA060 - I've got one here so I'll put it in when I do the replumbing and see how it goes.

 

I suspect the pill in my primary compressor->wastegate line is missing - the line looks hacked together and I can't feel one. Is this pill the same size as the one in BBOD line 1? If so I'll chuck it in there as well.

[Jimbo]

Yeah shouls be same size

[Ordex]

Tonight I setup the car as per Rob's last post, except running on wastegate pressure (with a pill in the line). I could feel it coming onto slight boost around 2500ish, and then a drop around 4500 (VOD? is this the VOD?) until more slight boost up around 5000 or so.

 

Given this encouraging development I thought to add the factory boost controller back into the mix even though I know it's not the best. It didn't make a huge amount of difference.

 

I'm still waiting for my boost gauge to arrive, so it makes it harder to compare between runs. Based on what I've read so far it seems adjusting the ECV should be the next thing on the list?

 

Incidently I also have a nasty amount of smoke coming from below the primary turbo area.

[Ordex]

Hey guys tonight I hooked up a boost gauge (at last). I couldn't find a free nipple on the intake so I tee'ed into the line that runs from the intake manifold to the BOV.

Did a few test runs down the highway - looks to be coming onto boost ok I think? Comes on around 2000rpm and is at 0.4 bar (6 psi) by 2500. However, it nevers seems to go above 0.4 bar. In the change-over range the boost drops right off before coming back up to 0.4 bar. I don't think I rev'ed past about 6000 to see if it went any higher.

 

Tomorrow I'll try bypassing the boost controller again to see if it raises slightly to wastegate pressure (think I read that is 8-9 psi?).

 

On a slightly different topic I also noticed tonight the boost died quite bad when changing gear while the car was in the change-over range. After a few seconds it came back on. Is this normal twin turbo behaviour? What's going on here? Is the ECV staying open after a gear change or maybe getting stuck open or something?

 

So many questions I know...

[Jimbo]

TT Rule #358 - Don't change gears mid VOD.  The sudden change of load and exhaust pressure elongates the VOD.

Just a characteristic of the TT system. Eventually you will learn to drive "around" it. All part of the TT learning experience!

Sounds like it's all running right but the boost levels seem abnormally low.

By any chance, does it sound like it has any exhaust leaks pre-turbo? I had problems with my old Gen2 GTB where I managed to crack up-pipes (piece of exhaust that sits between the turbo and the exhaust manifold) constantly until I got jack of it and had some solid one's made up. Tell tale sign was sluggish performance and it sounded a bit like a tractor in the engine bay. The stock pipes have a corrugated flex join and are just a shit design. Over time they tend to crack at the flex and leak out valuable exhaust gas. It's actually suprising how much of an effect they have on performance.

Also, make sure when your using the stock boost control, the restrictor pill is between the T-Piece and the compressor barb.

[Ordex]

What are the other 357 TT rules?!

 

I bypassed the stock boost control this morning, and pretty soon after the check engine light came on. After this I couldn't make any boost at all. Checked the error code and sure enough it was a code 66.

 

I've reset the ecu and replumbed the boost controller back in but still not making any boost. I'll try without the boost controller again later and see if there is any change.

 

I'm hoping the primary turbo hasn't let go or something drastic.

[Ordex]

Still not making boost even with boost controller bypassed. I confirmed the error codes were cleared (conntected black wires and CEL flashed steady).

I'm thinking whatever was making it only reach low boost levels previously may have finally let go.

 

Jimbo it's hard to tell over the noise of the exhaust if there is a leak, I'm not entirely sure what to be listening for. Any way to test for an exhaust leak or just have to jack it up and get under there for a close inspection?

[Jimbo]

Is it making any boost at all, or just not much?

Have you tried to reset the ECU via connecting the black plugs and the set of white (or green) plugs? 

As for exhaust leaks, carefully pop it up on some jack stands and turn it over. Make sure it's a cold start so you don't roast yourself. You'll just have to carefully move your hand around all the joins and feel for pulsing of air.

A busted upipe sounds like a tractor in the engine bay. It's the best way I can describe it!

I do however find it odd that a disconnected BCS throws the 66 code. 66 is the TT code of death and very hard to diagnose.

With the ECU, do you only have the Mines tuned one?

[Ordex]

Yeah Jimbo I only have the Mines ECU and I don't know of anyone else down here with a 7C ECU I could borrow.

 

Yeah its not making boost at all - boost gauge pretty well reads 0 when foot to the floor at any revs and doesn't feel like the sequential change over is happening. Last night after installing the boost gauge I was getting 0.4 bar max consistently on several runs.

 

Just to recap, the sequence of events was:

• Install boost gauge last night, got 0.4 bar
• This morning got 0.4 bar again (without any changes)
• Bypass BCS and breifly got boost twice, then got a CEL and no boost at all
• Checked code, found it was code 66
• Reset ECU and put BCS back in as per normal
• Still not boost, but also no CEL or error codes
• Try bypassing BCS again and still no boost, CEL or error codes

I'll have a go putting it up on the jack stands and feeling for any exhaust leaks and report back.

 

As an indication what would the expected boost be for this car? EJ20H with VF18/19.

 

Big big thank you for the help so far...

[Jimbo]

I would expect it would be at least running 8psi on primary and up to 12psi or so on sequential, but with the ECU you have, I would expect more than that.

I'm thinking now an exhaust leak might be off the table as you're not getting boost at all. An upipe leak will at least get you boost but a bit slower. Count that one out.

Something isn't happy and I'm not sure what it is. Throwing a code 66 means it has to be something in the solenoid box or the Differential Pressure Sensor is getting bum readings. If you're getting 0 boost,  the ECV or IntercoolerACV could be stuck open.

I'm pretty sure the IACV is held closed by vacuum when the car is off.

To check the IACV, pull hose 1 off the IACV with the car off and see if the IACV re-seats to open, you will see the arm return it to open. If you see it move, the vacuum tank is holding vacuum on it okay. If I'm wrong and the IACV closes when the car is started (default valve open when car is off), just check the vacuum on it with the engine on. It's one or the other, I can't remember.
 

The only other thing I can think of is a seized primary turbo. I know it sounds like clutching at straws but I'm running out of ideas! If you have the time, maybe at least get the dump pipe off the primary side and make sure the primary still spins. I have heard of primary's seizing and we've had a few on the forum over the years. At the very least, it's 6 bolts and some exhaust sealant and you can cross a seized primary off the list. Maybe check the primary wastegate isn't stuck open too by pulling the arm.

[Robbks]

Did you unplug the BCS from the wiring loom.....?
IF so, don't. That may the cause of your CEL

What have you done with the ECV plumbing?


what you need to do it put the car into sensor check mode.
Connect the single set of under-dash plugs (not the ones for checking codes, the other)
Then start the car and let it idle. it will cycle the fans on and off and will cycle all the solenoids and check sensors.
it will flash any current problems on the CEL

NOTE:
IF you connect the wastegate actuator to the compressor outlet nipple you will only get about 6psi (if your boost gauge is plumbed into the manifold)
there is a HUGE pressure drop from the turbo outlet to the manifold due to the terrible pipework from the turbo to the TMIC