Having used Webcon's AFS-1 Lambda read-out to good effect on the Mini, I have now gone further with the set-up on the Jag.
Webcon have two set-ups like this, I use the AFS-1 (ostensibly used on motorcycles) as it's smaller ; technically the systems are identical.
They use lambda-sensors of a type that are standard fitment on closed-loop fuel-injected cars, so give an instantaneous read-out that is sensetive enough to rattle the LEDs when you go over a bump in the road on a float-chambered motorcycle anyway.
I had initially intended to use the same read-out panel and switch it between the two cars, having even made a clip-housing on the Mini dash for easy removal, but I'm so taken with the on-board Game-Boy that I've bought a second one and have left the first one in the Mini as a permanent fixture.
This post is a little premature in that the car is getting a new interior at the same time, which is why I've been able to incorporate all the wiring, switches and read-out location modifications, so I've not used the system on the Jag yet.
However I'm confident that I'm on the right track and thought others might like to see how it's gone together.
The essential twist on the Jag is that we have to sniff two engines, one bank composed of cylinders 1-2-3 and the other 4-5-6, each running one-and-a-half carburettors, and this requires two lambda sensors - one in each exhaust collector.
And you then either need two read-out panels to follow both banks at once, or one read-out that you can switch between banks, which is what I'm doing.
I put the tapped bosses into the exhaust pipes a few years ago in preparation for this, it was relatively easy to find adjacent spots where there was space for the sensors and - above all - space to get at them with a spanner etc.
The wiring comes into the cockpit near the windscreen-wiper bottle on my RHD Series 1, via a spare grommet, and I chose to locate the Superseal-type plugs on the lambda sensors out of sight down by the clutch bell-housing.
I re-wired the AFS-1 with much thinner wires taken out of some RG45-type cable as the read-out panel only uses tiny currents to drive the LEDs, the original cable choice being dictated by robustness - whereas I needed to take the wires out through the top instead of the bottom of the instrument and this required some dexterity.
I used stainless piano-hinge to carry the LED-panel in the roof of the glove box, with a couple of carefully positioned centre-point blows to render it stiffer, and it stays put out of the way and almost out of sight when not required.
The lambda sensors use 4 wires, two being a simple heating circuit carrying a couple of amps, and the other two carrying the signal. The trick is to power both lambda heating-circuits at the same time, so the read-outs are permanently available, but switch the read-outs so that you can flick between cylinders 1-2-3 and 4-5-6.
I used one switch to act as on-off for the whole system, and a second switch to jump the read-outs from one set of cylinders to the other - and then hid both of them under the under-dash panel on the passenger-side of the car (made easier by having made new steel panels for all the under-dash area).
There is actually VERY little room for switches and wiring in this area, and in usual Jaguar fashion you have to be VERY careful not to overlook what-is-now-going-to foul-what-now-that-I've-modified-something.
But for once I didn't shoot myself in the foot and think I got it right first time.
I believe this will be a useful tool to improve the choice of SU needles for the car, just as it has proved to be on the Mini, and it's sufficiently discreet to be able to leave it permanently installed.
As in, Now You See It .......
........ Now You Don't.
