Boombastik

HI Guys, not sure if this has been covered before but just looking for the correct way forward

do I need to swap the entire wiring loom from my 2.5 to the MK1 for doing the engine conversion ?

I had a quick look and the ECU plugs in the MK1 are different and Im running ME ECU in the 2.5

so just looking for some advice or if some one can point me in the right direction with regards to the wiring

Im a good bit away from the swap as Im in the process of welding up the floor, apart from the dash and the loom the car is basically a shell just now

TIA

vtbandit

Vvt swap thread

check out this thread

Boombastik

thanks for the link, lots of info on that thread for sure, cant see where it covers the ECU plugs, do I need to buy a new ECU for the installation ?

Cutthroat912

You must not have read very well... the wiring is covered in the 2nd half of the very first post. Run the ECU that is in the car already or use a standalone unit like a Megasquirt. You can use the wiring harness from the donor car but reading more into that thread will try to sway you against that option.

Boombastik

thing is I am using motorsports electronics standalone ECU now in the mk2.5 so ideally I need to swap that over with the engine but as I said the ECU harness on the Mk1 is different, so would the other option be to get a MK1 standalone ECU that plugs in and then do the conversions to the harness that's currently in the car

vtbandit

I’m not an expert on this but I think the rule is to match the ECU to your harness and I agree with above that the public opinion is to not swap harnesses.

My 2 cents, if your switching to a vvt engine, buy an aftermarket ecu that lets you exploit some of its advantages.

Cutthroat912

Yeah, your best bet would be to get a standalone for the MK1 and make the necessary changes to the harness in that chassis. Recoup some of your money by selling the ME from the donor car.

Boombastik

right I get ya, so basically go back to ME who supplied my ECU and I need to get a new board that will fit the harness in the car and then make the modifications as per the thread to get the VVT to work

vtbandit

@Boombastik you got it.

Also, I’m not sure where you are geographically located, but cannot recommend this company enough to assist with making the wiring adapters.

Ballenger - miata specific connectors

Boombastik

that's a handy link you sent there thanks for that