No plans for forced induction on this engine, I'd quite like to try supercharging an essex but it won't be done on my everyday car...! Knock sensor is intended to provide some additional protction against fuel / air changes. inlet air temperatures were an issue in the summer when the air temperature sensor actually read as high as 80c on some occasions. At some point I will sort the airbox / filter out but its a job that has been repeatedly delayed by other more pressing jobs.
This post takes a brake from sanding and bodywork and takes a short interlude into the exciting world of world of wiring, This was a job I'd been hoping to tackle in July / August when I had planned to take the car over to the IOW so my mate Dave could give me a hand sorting out the wiring loom to cope with some upgrades...
The head gasket failure left the car immobile for the whole of work's summer shutdown so the opportunity came and went. A revised plan was pencilled in for a weekend in September when both Dave and I were free (rare enough these days.) Typically work then got in the way and we were stood up for production Saturday morning which left me with a day and a half to do what was probably 3 days worth of work.
Rather than cancel I decided to press on and see how much we could get done....
The objective was to modify the ECU wiring loom to accept the following additions: Knock Sensor, Camshaft position sensor, 3 more coil pack wires to allow for sequential ignition and to add twin Wideband 02 controllers, route them through the car, and connect them to the ECU, Then weld a boss to the exhausts to take the 02 sensors and finally test the system.
With the loom stripped off the car we started by running 3 more wires for the coil packs (correct coloured wire was sourced from eBay)
We then tried adding an extra 2 core shielded wire for the knock sensor and quickly rand into problems with the acrylic protection being too tight to accommodate the extra wires.
After struggling for a while trying to get the wires through, we decided to take the whole loom apart, this would make running the new cables much easier. Its a Y shape Loom the base of the Y is the ECU Plug & Relays, one fork goes onto the engine the other to the battery & coil packs.
With the loom apart adding the new wires was much simpler, we could then add some new bigger protective sleeving.
I'd bought some larger diameter sleeving with this in mind, its made by Vidaflex and is heat and oil resistant, I've used it where the loom goes into the engine as extra protection.
This photo is the loom going back together...
This is the ECU Plug gold terminals are ones we have altered / added, silver ones are originals.
Plug From the other side,
We spent a bit of time finding the best location for the knock sensor, this needs to be reasonably close to a cylinder, It is essentially a microphone once setup it should detect preignition and allow the ECU to adjust timing / mixture to compensate.
I've fitted this one to the head just above number 4 cylinder, which was also a convenient from a cabling point of view.
This photo shows the loom as it enters the drivers footwell,
There’s now an additional relay for the 02 controllers, they are connected to the main loom via the 2 4way plugs you can see at the centre rear of the photo. There are two controllers and 2 sensors as its a V6.
The O2 controllers are innovate LC2's and they will be concealed behind the panel that covers the heater matrix, they just fit without interfering with the mechanical heater control linkage,
The cable from the sensors uses the same cut-out as the original radio /dashboard braded earth, This brings the cables for the 02 sensors out in the gearbox tunnel...
Next stage was to find a spot to weld the boss into the exhaust for the 02 Sensors...
Heres how the tubular manifold looked as standard:
Idealy the sensor needs to be at the collector where all 3 downpipes meet, On a Scimitar with tubular manifolds this means a collector just past the outrigger, unfortunately there is not enough clearance to to fit the sensor to the top of the manifold. So as a compromise we came up with the following sideways position,
Here it is once the boss for the sensor had been welded in...
The cable is routed via the outrigger, along the chassis. Dave welded some new tabs on to hold the wires. I’ll give them a coat of paint before the car goes back on the road.
The passenger side is clipped along the gearbox crossmember,
A future improvement would be to have the collector for the exhaust a bit further forward, this would allow the sensor to be fitted in the channel of the outrigger better protecting it from debris. Something to consider when at a future date I improve the exhaust...
With the sensors fitted and the wiring all connected we started the car and with the laptop connected we were able to view the AFR Live, The spike in the readings corresponds to me revving the engine.
After some consulting the manual,
I managed to get the ECU to register the waveform from the o2 sensors,
which proves that the wiring is all working as it should however there Is something not quite right with how the ECU interprets the voltages. So I've left the Active feedback turned off until I can ring Omex or get the ECU setup by someone who knows what they are doing...
Still not bad for a day and a halfs worth of work.