Thinking to fit efi on mk3, it has a mfi s1 loom fitted and I have a mk4 efi cabby as a donor.
Do I need to split the efi loom right back to to the ecu and where do I join it in to existing loom?
Can I use the cabby engine and just swop blocks to make it turbo?. I've looked at the sticky but still a bit lost.
Cheers for any help.

 

I think most will say pull out the full s1 loom and fit the efi one. That's what I'm in the process of doing now

 

Are you going to fit the mk4 dash or change plugs?

 

If you haven't thought about it and depending on your budget of course it might be easier and more reliable to fit new management, whatever your local/chosen tuner recommends?

 

I done it once a mk4 cab loom into a series one and had to rewire all the stalks

 

If you haven't done so already have a good read through this thread:

https://passionford.com/forum/ford-e...5-04-14-a.html

It will have many answers to questions that you will have.

Swapping looms is fairly straight forward, but whilst the loom is out on the floor its a perfect time to check every thing is in good order and repair if needed.

Rob,

 

I decided to fit a base model loom and split the efi loom, I had the wiring all connected and ran lives from battery to the eng man lives and connected earths below wiper motor it ran fine.

Now I've moved the wiring inside the car and have connected lives in to ign live and the earths are connected to drivers speaker well and the two earths from the ecu are earthed to bulk head and I have no spark. Both relays click as do eng sensors when I power them up but no spark. I'm charging the battery just incase its not cranking fast enough.
Should I run all the earths back to battery?

 

Good move. When I refurbished my loom I actually made 1 good loom out of 2. The management sub-loom in an XR3i EFi is easily split out once all of the tape is removed.

No need to run the earths to the battery. The only other one to mention is make sure the earth to the EDIS is connected to the body. On an XR3i EFi loom it bolts to the terminal by the horns.

Lee

 

Problem was moisture in the amplifier on top of the coil pack if that's what it is, changed it and all good. Hoping to have it all done tomorrow

 

Coil suppressor?

 

That'll be it, cheers