legacy conversion problems

[rex-leggy]

hi there i have in the last mounth rebuilt my 96 gt wag . also in the prosess ive converted it to single turbo but

there are two hoses that i do not no where they go. its in the very back left of the engine bay . its a valve or sumfin bt not sure . the hose numbers are 21 and 22 . any help would be appriated because id really like to start it tomoro haha ;D .

[Leighos]

Sounds like the differential pressure sensor, it tells the ECU the pressure difference between the two turbos.

You must connect this for it to run.

Cant remember which one it is (21 or 22) but its the pink striped one that needs to connect to positive pressure straight off your turbos compressor housing. The yellow one you can just leave vented to atomphere for now.

It will run, but believe me it will throw CELs at you from time to time. Mines been like that for almost a year and I'm so sick of it I'm going to change to a single turbo ECU. I've done a diagram of how I've set mine up, do this and it will at least be drivable, but look into doing the ECU conversion, its the only way to fully solve all the issues of going single turbo with an EJ20H.

http://i635.photobucket.com/albums/uu74/leighosative/BoostSensorControlDiagram.jpg

[rex-leggy]

at the moment i hav piped it up without it . is it possable for me to just t it into the pipe on the outlet of the turbo . or is this the only way you have found it to run?

[ReubenH]

Er, you don't need the differential pressure sensor to run at all, single turbo ECU's don't reference it.

Unless you're trying to do this on the TT's ecu... in which case, lol, have fun.

[Leighos]

Yea I know its not used on a factory single turbo :

I was assuming he's just done what I've done and just done a 'mechanical only' twin turbo to single turbo conversion, in which case he will need to do something with it.

Really the only solution is to go single turbo ECU.

[ReubenH]

So how is it on a TT ECU then? does it control the boost fine enough and all that? And CEL's?

[Leighos]

Yea its perfectly drivable and the ECU handles boost control ok, its just that under load (like 4th or 5th up a long hill, with boost on) it will cut for a sec, CEL on and goes into safety boost mode. Codes that come up of course are 66 (no shit!) and 65 for the DPS.

Its really annoying at first, but you quickly learn to change your driving style and work around it.

Still, it sux arse though, hence why I'm converting to single turbo ECU!

[ReubenH]

You got a 4 plug or 3 plug?

[Leighos]

I've got the 4 plug, standard issue on the early BD5a's with EJ20H as far as I'm aware.

I've got a couple of BC5 RS ECU's and a 3 plug (V3/V4 WRX) to play around with.

Going to make up a harness adapter to make things a bit easier.

Koom also suggested to go the 3 plug if I can, bit better for expanding with mods in the future, I think hes right there.

I'm using that pinout of yours for the TT ECU, thats the only one I can find (after many long hours of googling!!) How reliable is it?

[rex-leggy]

ok so i just got home from a nights driving couple of problem haha got the 66 code but as you said ya do get the hang of it. and the car only runs about 4 psi which is good cz im runing the engine in . and it seams to be runing a bit rough. so im after a wrx computer am i? wat version just any 3 plug ecu correct? also had to fix a dodgy oil return because i forgot to seal it . was lots of fun to get to but i managed to get to it wihout removin turbo yaz!!! but converting it to single was quite cheep i thought $330 for custom downpipe and single turbo exaust and vf8 turbo for free off ma mate (cheers cuillin!!) anyone out there got a ecu for sale?

[Leighos]

I'd say the lack of boost means you havent got the factory boost control quite right, 4-5psi is the factory wastegate spring and the boost solenoid overrides this. I guess you could always use some other means of boost control ie bleed tap or EBC.

I'm not familiar with the 3 plug ECU's on the later model EJ20H's, I've never even seen a pinout for one of these, you could be lucky and it might be the same as the 20R's in which case you can follow Reubens conversion thread and all will be well.

[ReubenH]

 Leighos']

Koom also suggested to go the 3 plug if I can, bit better for expanding with mods in the future, I think hes right there.

I tend to agree with that.

[quote name='Leighos said:

I'm using that pinout of yours for the TT ECU, thats the only one I can find (after many long hours of googling!!) How reliable is it?

Which one, the 3 or 4 plug TT ecu pinout? The 3 plug is fine, i also posted the STi 3 plug pinouts, the match perfectly. If you're talking about the 4plug TT ecu, PM koom, he has a high res version and some more stuff about them apprently.

[ReubenH]

 rex-leggy']

wat version just any 3 plug ecu correct?

I'm not familiar with the 3 plug ECU's on the later model EJ20H's, I've never even seen a pinout for one of these, you could be lucky and it might be the same as the 20R's in which case you can follow Reubens conversion thread and all will be well.

Depends, tell us what ECU you got in there at the moment rex-leggy (What's your real name btw?)

96 was, as far as i'm aware, the cross over year to the 3-plug (manual) 1-plug (auto) ECU's. Now, weather it was ONLY the GTB/EJ20R that got the 3-plug, or both the EJ20H and EJ20R's that got 3-plug, i have NO idea. So yeah, dive into that footwell and tell us what you got in there. It may also be that you are pre 3 plug (i'm putting my money on this).

[quote name='Leighos said:

I'd say the lack of boost means you havent got the factory boost control quite right, 4-5psi is the factory wastegate spring and the boost solenoid overrides this. I guess you could always use some other means of boost control ie bleed tap or EBC.

Well, for the TT's, the "turbo wastegate duty solenoid" is in the passenger side wheel well/under fender. I bileave rex-leggy will be using the "secondary turbo] exhaust valve duty solenoid" for his boost control, since that's the one sitting next to the turbo (in the BBoD). This may be what's wrong, i found with the 3-plug setup at least, that the single turbo ECU was talking to the fender BCS, not the BBoD BCS. Now... i don't know how the TT does boost control, i read a write up about it but have forgotten. So i don't actually know if theres' a fix, but i suspect there may be a simply wiring fix like in my single conversion thread

My recommendation though, is single turbo ECU only, to run single turbo.

[rex-leggy]

ok ill find out how many plugs the ecu has. running alot better now ive fixd the intake leak . i removed the pcv valve system so it was leakn strait out the hole

[rex-leggy]

btw the names josh i live in chch .

[rex-leggy]

3 plug ecu . guesin thats a great thing

[Leighos]

Hopefully it is See if you can find a pinout for it and compare it Reubens GTB pinout.

Just out of interest, what is the number on the casing?

[ReubenH]

 rex-leggy said:

3 plug ecu . guesin thats a great thing

Oh you bet it is. And your car, is a BG5B GT is it? What's your applied model code and engine code? And do you have grey top injectors, or yellow top injectors?

[rex-leggy]

greay injectors . dont have the engine code tho because its a diff engine in the car now

[rex-leggy]

so things are different now when i lookd the first time im sure i saw three plugs lol . either im blind or over the last two nites my ecu has sprouted another plug. so it is actually a 4 pin ecu.

it has a blue label that says

7c

22611 ab386

a18-000 dc9 (6228)

any ideas where to go now?

[Leighos]

Hows you auto electrical skills? You'll be doing the same conversion as what I'm doing then.

First thing is get as much info as you can get before you even look at your ECU and loom, get pinouts etc and think about exactly how you are going to do it.

Get yourself the appropriate ECU, I originally was going to convert to 4 plug EJ20G (early Legacy & WRX) but have since decided

to go the later 3 plug type (way more room for future upgrades).

Think about making an adapter harness to make the swapping of wires a bit easier, and you're also no hacking into your own loom this way too. I just got an old burnt out ECU, salvaged the sockets, then got some loom plugs and started wiring the two together based on the pinouts I have. Fun times ;D

[Guest]

Oh dude u got the same ecu as me 7c but mines yellow (dunno what that means) im making an adapter up as well to suit the v3/4 sti ecu i think ive almost got it all sorted apart from a couple of things, will keep u informed.

[rex-leggy]

im an electritian so thats no probs just need the diagrams an im sweet from there lol . where would i find these

[Leighos]

Ok this one will help convert from the 4 plug EJ20H ECU to a 4 plug EJ20G

Then you can get the pin outs for whichever 3 plug ECU you're going to get and go from there. Google is your friend here.

Here are some that I've used for the 3 plug stuff.

http://www.northursalia.com/modifications/misc/wiring/wiring.html

[rex-leggy]

is the only way to do it twice ?