V8 ECU mounting positions in a Ninety

[mickeyw]

For the last couple of years my Ninety has had a serpentine 3.9 from a Discovery under the bonnet. When I bought the engine it came with the Disco ECU and engine loom.

The ECU is currently fixed to the upper face of the passenger side footwell, cos that's as far as the loom would reach.

To date I have had a couple of instances where I was worried about water levels inside and submerging the ECU. I have been wondering what options are available to extend the loom to allow a higher location, ideally I would like to move the ECU to the bulkhead behind the seats.

I know there are loom extensions available for the td5, what about V8s?

Thanks,

[FridgeFreezer]

Just buy some wire (preferably the correct colours) and make it as long as you like - my ECU is on the ceiling along with all my switches & warning lights.

[mickeyw]

Just buy some wire (preferably the correct colours) and make it as long as you like - my ECU is on the ceiling along with all my switches & warning lights.

Thanks Fridge,

I assume you mean cut the wires and solder extra bits in between? Time consuming yes, but perfectly do-able as long as I wear my special patience hat and have soothing music playing in the garage

The wires from the o2 sensors appear to be shielded. How important is this and will cutting and soldering them affect operation?

Any other useful little bits of advice from someone who has obviously done this once or twice would be appreciated.

Cheers,

[FridgeFreezer]

Cutting and soldering (and heat-shrinking) is the best way, yes. For the O2 sensors it's preferable to use the shielded wire but probably not essential - all the MS installs I've done/seen use normal wire for O2 sensors and seem to work OK, however I'm sure Lucas can find a way to make it unreliable enough to need shielded wire You could always switch the tune resistor to a non-cat one (no O2 sensors) and remove what is a potential point of failure with those systems, a dodgy lambda sensor seems to be able to totally confuse Hotwire for no good reason

Depending on the install you could also probably lose a fair few wires that aren't required, although only a good trawl through the circuit diagram would reveal that. If you strip away all the peripheral carp, hotwire looms aren't too bad. They get even more tolerable if you strip off the ECU and AFM

Other tips - soldering in a cold footwell is no fun, you'll need a decent iron and if possible to get the truck somewhere out of the cold & wind. For uber-bling use glue-lined heat shrink, then some convoluted sleeve or similar to protect the loom afterwards and make it look proper. If you can't be bothered to source all the correct colours, at least use numbered collets or suchlike. Hotwire looms use the same code several times, you have black with a yellow tracer, and then black with a dotted yellow tracer, etc. which makes life a bit interesting - cutting & joining one wire at a time is the safest way.

[Hybrid_From_Hell]

Moving the ECU is one option

The other (as I have done) is to place the ECU in a fully waterproof container

When I did the MS I took the opportunity of doing both

Worth a thought ?, my "Box" is a Cast ali affair with a O ring built into a grove on top and bottom parts and screws on all 4 corners

Pics in the MS Thread

Nige

[FridgeFreezer]

The other (as I have done) is to place the ECU in a fully waterproof container

The problem is waterproof containers very rarely are, especially when you drill a big hole in the side for 30+ wires to pass through it can be done, and a waterproof box will certainly keep the worst out, but it's unlikely to survive proper submersion for a long period.

[Hybrid_From_Hell]

^^^

Yep good point

However what I did was to use a special Gromet suited to the appication - the bundle of wires passed throught and then the plug soldered on -

or more accurately YOU soldered it on .

This way then the seal is prob about as waterproof as you can get, even running a breather in it to aviod condensation etc.

Thus igf you are planning to EXTEND your loom this does have its merits ?

Nige

[mickeyw]

You could always switch the tune resistor to a non-cat one (no O2 sensors) and remove what is a potential point of failure with those systems, a dodgy lambda sensor seems to be able to totally confuse Hotwire for no good reason

This is feeling more do-able by the minute.

I'm curious about the tune resistor business, it would be handy to not have to worry about O2 sensor problems. Where do these bits reside? Please tell me more.

I assume to bin the ECU and AFM you mean go MS I have ideas about MJ in the future but it's early days yet, few other things to get done first. I quite fancy soldering up my own PCB, SMT stuff is pretty familiar to me.

My setup is pretty standard except for single point Leonardo closed loop LPG. This has its own O2 sensor, no shielded wires on that. I only run on petrol for starting, or if the LPG system gets the hump (rare), or of course I run out

I have already binned a good few redundant wires from the loom when the engine went in, just got to figure out which ones they were again.

Thanks,

[FridgeFreezer]

Not sure where the tune resistor is but if you search for "tune resistor" you should find all you need to know, it can be replaced with a stock resistor (390 Ohm 1/2W rings a bell but don't quote me) which tells the ECU what to do. And yes, I do mean go MS although if your LPG system is a "dumb" vaporiser type and you rarely run petrol you're probably just as well going MJ and forgetting about the petrol fuelling. If your LPG system has injectors, it'd be good to see someone finally run petrol & LPG from one ECU as it seems like such a good solution.