F

Fango

New Member
Engine Conversion from 3.5 to 3.9:

So today I pulled the 3.9 EFI wiring loom through the bulkhead to see where I could mount the ECU. From the pics below, does anyone know if I actually NEED the extra plugs that branch off? I've read somewhere that I could get this running with 4 wires, but really don't want to chop anything off I'll regret.

DSC03653.jpg

DSC03655.jpg



Also, for those of you running a speed transducer/speed sensor, where and how did you mount it? I couldn't find any plugs near or on my transfer case. Here is what I'm working with.

DSC03649.jpg


Many thanks!!

Matt
 
Last edited:
Hi fango,

i am looking to do the same as you was just wondering how you got on with the 2 extra loom plugs and speed sensor???

dont think you need the two plugs???:confused:

any info would be great

cheers...
 
Have you tried looking at a wiring diagram for a 3.9efi Rangie or Disco? That should have it sorted. In basic terms you need power feeds for main efi relay, fuel pump relay, various earths and the rest should be straight forward.

The ignition is a separate system to efi but there is the signal wire from the coil. You will need the speed sensor. Apart from that you just need to make sure you know which wires go to which sensors.
 
BTW it looks like you've pulled the plug for the air flow meter into the cab - it needs to be in the engine bay.
 
classic kev said:
BTW it looks like you've pulled the plug for the air flow meter into the cab - it needs to be in the engine bay.
Click to expand...

Thanks for the help guys. The airflow meeter is already hooked up, so again, I'm not sure what that plug is.

I've decided to reroute the wiring underneath and up into the driver's seat box in the meantime.

I have looked at all wiring diagrams for the Disco and RR, but still can't figure out the plugs pictured. I think I'm going to get a known landy auto electrician to sort this out since I need it to run soon. Hopefully, I'll be able to watch and learn a few things. I'll keep you posted.
 
What year is that EFI loom? I've pulled my spare loom out and it doesn't look like the one in your photos.

For a 3.9 Hot Wire injection loom there are 8 injector plugs, 1 coolant thermistor plug, 1 fuel temperature thermistor plug, air flow meter plug, coil signal wire, stepper motor plug and throttle potentiometer plug. Oh and an earth strap.

Inside the car, there is the big plug for the ecu, 3 relay bases: Main efi power, fuel pump and I think the other is for the air con fans (if fitted). There is a small connector for the tune select resistor, a diagnostic plug and a pair of fuse holders. The only other plug I can see is a white plastic 8 pin plug.

Is it possible you have another loom attached to the efi loom?
 
The black plug in your photos that I mistook for AFM is possibly the plug for cruise control; you might have the cruise loom as well as the efi loom there.
 
One more thing, the wires on the tune select resistor appear to be white, this indicates the car has/had cats. Make sure lambda sensors are attached and working or it won't run very well if at all. If not using cats, change tune select resistor to 470 ohm to run non-cat fuel map (open loop).
 
matt has got a disco loom with spider connection major reqire of the loom to remove the spider link simple
 
Vougese, I'll leave that to you...I was tempted to start unraveling things, but I couldn't find a good diagram for it. I bought the engine and loom from a kit car so I had to figure out/guestimate the year and model it came from since previous owner wasn't sure. After a few Haynes manuals and ill-fitting parts here and there:frusty:, I'm pretty sure the loom and engine are from a 1995 and on disco.

I don't have a correct year speed transducer, or o2 sensors so if I need any specific parts lemme know.
 
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firstly unless you are fitting cats don't bother with lamdbas unless you have gas? can get you the correct tune resister
speed transducer is simple order a speedo cable for a ealy range rover 3.5 with efi and i will mod that for you have you got an inertia switch to trip the fuel pump?

all easy when you have done them before see you in a few weeks should have it running in a day
 
vougese39 said:
firstly unless you are fitting cats don't bother with lamdbas unless you have gas? can get you the correct tune resister
speed transducer is simple order a speedo cable for a ealy range rover 3.5 with efi and i will mod that for you have you got an inertia switch to trip the fuel pump?

all easy when you have done them before see you in a few weeks should have it running in a day
Click to expand...

No cats, no gas. I have a RRC speed transducer and a NAS defender speedo? If you don't think that will work, I can order what we need. Can't wait to get it back on the road...only drove her for 3 months or so before the old engine went.
 
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