NAlover

Well guys i'm in the process of finishing my swap (k20z3 EJ)
to make story short...
i need to buy 02-04 engine harness to complete my swap

came across a K20a3 (EP3) engine harness, locally for a low price
i Know the EP3 came 5 speed and off course the engine is different than
a K20z3... LSD : )

i also heard something about K20a3 dont have the reverse lock-out mode (Been 5speed)
other than that. Are any other differences in the harness??

well my question is: will the EP3 engine harness work ????

Thank you for your time

NAlover

Anyone with some knowledge that can contribute on my build...??
Thank you

JW racing

What transmission are you using? I would just get a 02-04 RSX Type S engine harness

dschybrid

The engine wiring harness will work.

You will not have the reverse lockout.

Everything else will work fine.

There are also a few other things you will need to swap out other than the engine wiring harness.

Throttle body and the ECU are the main things. Depending on what you are going to do about the shifter you can either take the Si shifter assembly and bolt that to the top of your tunnel and use the Z3 shift cables.

OR

You will have to change the gear selector mechanism ontop of the transmission to that from a K20A2 6spd. Because the transmissions select gears in a different way you can't use Type S cables on the Z3 transmission. If you change the selector, you can use Type S cables and the RSX shifter or Hybrid Shifter.

-DC

NAlover

Its a K20z3 with 9000 miles.
gutted 1994 DX EJ

well i really like the K20z3 engine
-better cams
-Intake manifold
-LSD
-9000 miles on the engine

but it requires more work that other swaps.
-ECU = got a Type S + Kpro (gotta finish paying) : (
-T.B = got a Type S
-the engine harness = (will get today) K20a3
-transmission = i got everything from a Si (shifter braket, cables). So i bolted the braket
in the chassis and it works perfect (doesnt look too pretty but it gets the job done). I'm also using a S2000 cluster which i got all the wiring diagrams to make it work and the Box to adjust the Temp on the cluster.

will post pictures when i learn how to post them.

WhiteSol

There is a difference between the Z3 and A3 TPS sensor wiring, you'll have to switch the positions of the TPS wires if you use an A3 harness on a Type-S TB. The A3 TPS sensor is mounted on the opposite side of the TB by comparison, so the % throttle value will be inverted because the sensor rotates in the opposite direction. I believe the two wires are Yellow/Blue and Green /Yellow but don't quote me on that...

Remember also, you'll need to wire in a speed converter (link) if you plan on using the Type-S ECU with the K20z3's transmission.

NAlover

i would like to get more details on the TPS sensor since today and
tomorrow i will be doing my engine harness. TUCK

I am also tucking everything on the entire vehicle.

NAlover

how many plugs do the K20a3 engine harness has??
i counted 31 plugs besides the 2 that go to the ECU

Cidone

a couple things to think about. First what trans are you going to run? you can use the lsd out of a Z3 but you can not use the trans housing. the only swap mounts that are used are for RSX,RSX-s and base model 5 speed trans. Another thing is The cams out of a Z3 are the same as a A2. if your looking for a stock upgrade you can use Z1 witch are revised Type r cams, 04-05 tsx cams witch are slightly bigger on the exhaust side and or the best stock cams you can get 06-08. here is a good link you can read up on.
http://www.k20a.org/forum/showthread.php?t=43261

Cidone

Also that Z3 motor has balancer shafts oil pump like all the K24 motors do. you will need to convert it to 02-06 oil pump and pan to make decent power.

NAlover

i'm doing a full swap meaning z3 long block+transmission

i do not plan on touching the internals, since the engine only has 9000 miles.
i will eventually get cams later on, but they wont be OEM cams for sure.

there are plenty of people runing K20z3 (full swaps) so idk why you are saying the transmission wont work.
there are also quite amount of people making decent power with STOCK k20z3 just bolt ons.
without changing anything internally.

how much WHP you call decent power.???

Cidone

well if you have read the last honda tuning they have a 08 si with custom header and exhaust. with aftermarket cams making 220whp i think. There alot of stock A2 motors out there making in the 230s whp. the trans case on a z3 has a diff mounting point for the trans side mount. Unless hasport makes mounts for that swap. i might be wrong. you might also need a A2 chain side mount bracket. Also the whole reason honda made the RBC manifold was because the balancer shafts in the oil pump took so much power away because of the weight they had to design a manifold that flowed better to make it back.

there are Z3 motors out there stock making in the 240s whp but you got to do some moding....

NAlover

remember that 08 Si's dont have Kpro, they only have the Reflash therefore
Z3 motors make more power when done in other vehicles with KPRO.

there are plenty of people running 12's on stock K20z3 with just Bolt-ons+kpro. and thats my goal.

quick question:

1- How many plugs going to the ECU do 02-04 K20 engine harness have?? 2 or 3???

it will be appreciated.
It's just a 1 man garage, also kinda new to k series world...

DC5Smilez

I know this is my first post and you probably wont take it for much but I just joined.
I have a base RSX with I/RH/E/RBC/K-pro.
The K20 engine harness has three plugs going into the ECU and the A3 harness will work with the Z3.
Plenty of people have done it on CRSX.
The only thing is you will need a TB from the A3,A2,Z1 because the Z3 uses DBW if I am not mistaken.
Also with the TPS sensor on the A2 or Z1 TB, you have to rewire the wires going to the TPS if you use the A3 harness.
The wires are in the sequence 123 and you have to switch them to 321, so just switch the first and third wire it is really easy.

NAlover

thanks for dropping your first post here...
and yes you are right. the engine harness does work

somehow the engine harness i got has 2 plugs going to the ECU?
i need to make sure whats going on here, because if i got the wrong
one i will need to get it changed.

Thank you

0xenocron

2 plugs on the harness go to the ECU, the third plug the ECU needs is an interior plug or comes on the conversion harness if you are swapping this into an older vehicle.

kevino002

so since its been a few months, how did the swap turn out??

Hazeburner

doing this exact same thing right now