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EFI conversion - location of ECU

PostPosted: Fri Nov 26, 2021 3:06 pm
by nwbaxter66
In the process of using the Thanksgiving break to get back to my +2 rewire and EFI conversion.

Question - I want to mount the ECU outside of the engine bay
My two current ideas are either inside the glove box or under it, fixed to it.
Under the glove box avoids cutting up the glove box, but means leaving the ancillary cables hooked up all of the time.
It is an Emerald ECU and I have an unfinished loom so wiring length is not driving anything.

Is there a better location or are they all much of a muchness on the passenger side.

Interested in thoughts.

Finally got the fuel system finished, used the combination swirl tank and bosch fuel pump from 034 Motorsport, with return and placed the fuel pressure regulator in the trunk to save some engine bay space.
My brother was kind enough to hand deliver the Jenvey Heritage under carb linkage that was necessary because my +2 bonnet has no "hump".

Starting to see a little progress.

Re: EFI conversion - location of ECU

PostPosted: Fri Nov 26, 2021 3:16 pm
by mbell
nwbaxter66 wrote:Is there a better location or are they all much of a muchness on the passenger side.


There is quite a big space on the outside of the glove box, on side of the car that protrudes up the side of the engine bay. I am not familiar with the Emerald ECU but I think it might fit well up there, with wiring point to rear or floor of car. It should be dry location that is out of the way but also accessible with out too much effort.

Re: EFI conversion - location of ECU

PostPosted: Fri Nov 26, 2021 5:15 pm
by pptom
My Omex is in the glove box on my +2. Only mod required was a 3/4" diameter hole in the back of the glove box for the wiring to pass through. It then passes through the original bulkhead wiring grommet hole just underneath.
Just sits loose in there, you will love the injection upgrade once it's mapped. I think mine only made about 10bhp more, but driveability is in a different league to 50 years old Weber's and I'm sure it only uses half the fuel now.

Re: EFI conversion - location of ECU

PostPosted: Sat Nov 27, 2021 1:27 pm
by DavidLB
I’ve put mine on the bulkhead behind the glove box, it is fairly well protected there. David

Re: EFI conversion - location of ECU

PostPosted: Sat Nov 27, 2021 8:14 pm
by nwbaxter66
thanks all, good advice
Now I have the fuel system and ITBs test mounted I can work on sizing the loom runs.
Nick

Re: EFI conversion - location of ECU

PostPosted: Sun Nov 28, 2021 7:54 pm
by stugilmour
Of the already outlined choices, I like the gap between the glove box and inner fender.

I used this spot to mount my MSD ignition box, which I think is pretty close to the Emerald ECU size. I did test fit a cardboard box to model the Emerald ECU and it looked good to go in the same spot. I opted to stay carbureted instead, but that location was my first choice for the ECU.

When I wired the MSD I ran its multi-wire loom so the plug is facing out; very easy to disconnect if removing the box. I used a metal mesh Dollar Store basket lined with foam to hold the box. The whole affair can’t be easily seen or bumped.

My glove box presently holds several fuse and relay blocks, which is a great location for that stuff as it all comes out with the dash.

My thought was it may be better for future service to keep the ECU and injection wiring totally separate from the dash and running through a new dedicated bulkhead hole behind the glovebox. Lots of room there to drill the bulkhead.

One idea I had was to get gray coloured expandable loom sheathing (the stuff like a Chinese finger puzzle) for all of the injection wiring runs so that is completely separate from the other wire runs and easily ID’d later. Not a stock look, so opinions may vary.

All the best with the project. I wanted to try fuel injection, but figured I hadn’t given my new Weber’s enough of a chance.

Stu

Re: EFI conversion - location of ECU

PostPosted: Sun Nov 28, 2021 9:36 pm
by nwbaxter66
Stu
Thanks
Same idea on keeping EFI wiring and loom separate - I think it will make life simpler in the long run
I have an OEM style replacement loom but keep on having second thoughts about modifying it , it may look original but what a nest especially with three fuse boxes and the wiring around the relays
I think I may use the wiring but upgrade fuses and relays
N

Re: EFI conversion - location of ECU

PostPosted: Tue Nov 30, 2021 1:21 am
by tonyabacus
Hi Nick
Just picked up we are corresponding elsewhere.
As for your wiring issue, I think it better to try and keep your OEM loom separate and as far as possible and unadulterated with other cables. I just had to rewire my Elan because the previous owners had turned it into a real rats nest, adding cables of various colours but no record of what they were for.

Making up your additional loom is not hard and you can either run it in some flexible plastic sheathing or better still there is like a knitted version of the sheathing which expands as you add more cables, but it keeps it separate and makes it easily identifiable from the OEM. When making up a new run of cables I run them inside a small diameter plastic sheath, I then run these inside one of these expanding sheaths alongside the OEM, so in effect have a separate little loom for additions, which keeps things tidy. I then print up some very small labels and add them to the new cable runs in a couple of places to make tracing easy later. You can buy cable markers that stick to the cable if that is easier.

What I also found invaluable was to have an A4 copy of the wiring diagram and then add on to it the new loom or additional cables (needed more so now as old age and lost memory cells take their toll). The kindest thing you can do when you sell a car is to pass on these diagrams, with all the mods and updates.

Tony

Re: EFI conversion - location of ECU

PostPosted: Tue Nov 30, 2021 1:28 am
by nwbaxter66
Tony
Makes a lot of sense
Thanks
N

Re: EFI conversion - location of ECU

PostPosted: Fri Dec 10, 2021 7:56 pm
by Bigbaldybloke
Not sure if you re aware but this split loom cover may be useful for your wiring mods