Turbo engine looms

[--Rogue--]

People say the wrx EJ20T and the legacy EJ20T is the same engine, the only difference is the intercooler and the turbo is that true?

So the JDM EJ20T from the legacy can use the engine loom from the UK WRX?

[Huffer]

it depends on the year. And not all engine designations are created equal.

EJ20T isn't the correct engine code:
http://en.wikipedia.org/wiki/Subaru_EJ_engine#EJ20T

[--Rogue--]

The wrx engine was from a 93 wrx in the uk and for the legacy jdm engine is i think is 96-98

[Huffer]

Get the engine codes...

[decke48]

93 wrx is mostlikely an EJ20G 96-98 legacy is and EJ20H or EJ20R

[--Rogue--]

Yup the loom is from the WRX EJ20G and going with the legacy EJ20H will that work..

[subba]

the EJ20 G k and R uses the 3 plug (Mt) ECU harness, IIRC the r only has 2 wires to be jumpered to be compatable with the K & G.

The H i think is obd2 (4 plug mt)but the ones mentioned above is OBD1

[Reuben]

the EJ20 G k and R uses the 3 plug (Mt) ECU harness, IIRC the r only has 2 wires to be jumpered to be compatable with the K & G.

The H i think is obd2 (4 plug mt)but the ones mentioned above is OBD1

Not quite right there sorry.

To the OP, for the V0-2 WRX/STI and the Gen 1 legacy, yes the share the same engine, the EJ20G. The legacy got a water to air intercooler, coil on plug, that sorta thing... while the WRX got a shitty little TMIC which is probably the worst top mount ever made, and coil packs/wasted spark etc.. There are differences in the ECU's and wiring.. The legacy has stuff to controll the water pump for the legacy's water to air intercooler, the WRX one does not.

Subba. In short pre 96 = 4-plug, 96-98 = 3-plug, except the auto legacy's. - all OBD-1

The less short explanation:
For the impreza's. Pre 96's (V0-2)were EJ20G/4-plug. 96-98 (V3 and 4) EJ20K/3-Plug setups.
For the legacy's, the gen 1 was EJ20G/4-plug just like the early impreza's. When the gen2's and TT came along, all were still 4-plug, but had a different and unique/oddball pinout for the TT system. Post 96, just like the impreza, the legacy moved to the 3 plug, but only for the manual EJ20R's, the auto's got a really f'n odd single plug.

Regarding the difference between the WRX and Legacy 3-plug looms. It seems the 3-plug loom was designed to work on all. So every pin is used with the Twin Turbo. On the single turbo, all the TT pins are blank. And on the non turbo's, all the turbo pins are blank again. For the pins that the legacy and wrx do share, the only difference is that the legacy has 4 ignition wires (for each of it's coil packs), while the impreza's has only 2, thus runs wasted spark.


f***. i've gone and done it again :oops:

and shortened it :roll:

[subba]

Subba. In short pre 96 = 4-plug, 96-98 = 3-plug, except the auto legacy's. - all OBD-1

I figured, i have a 96 WRX 20G (was in it lol) and its 3plug and my 20R is 3plug and my buddies 20K is 3 plug. ( i have no clue about the pins so thanks for the info still learning :grin: )



f***. i've gone and done it again :oops:
Yes you did :)

[Reuben]

I figured, i have a 96 WRX 20G (was in it lol) and its 3plug

Wait, what? Are you sure that 20G had a 3 plug? Easy way to tell a 20G is the writing on the rocker covers (says 4 cam or 16 valve or something), and the casting marks on the block. I'm 99.9% certain no 20G ever had a 3plug ECU. But some were retrofitted after market, My mate wired in a 3-Plug on his old 4-plug RS for example. It's a good way to get an extra few pony's.

[subba]

I will double check when I go home, I know the plate under the bonnet on the passenger side says ej20g etc etc and the harness was 3 plug....