Illy coffee can O2 sensor

[JohnJL]

So this isnt 911-specific, but it does involve my 1971 Targa S with Webers. I have a few carburated cars (the 911s, ATVs, motorbikes and a 1974 FJ40) and have grown comfortable with getting them working reasonably well. However it has always been through the traditional methods...ckecking plugs, richening up idle intil revs drop, sync tools, etc. I did all that with my targa after some winter updating including an new M&K muffler. I never had an 02 sensor on this car in my 15 years' ownership through many rallies and track days.

I have been spending a lot of time recently on different EFI systems and wanted to check my carbs and ease set-up going forward. I had installed an Innovate MTX in the gauge cluster of my autocross car, but I find myself using the tunerstudio dash instead, I decided to make up a portable O2 sensor, gauge and logger I can take from car to car, as well as tune across separate header.

I removed the gauge from the car, but left the ABS face intact. I may reinatall it later.

I looked for something to house the gauge and controller unit, both ABS pipe and booster hose were just off in size. Then I spotted a spare Illy espresso can my wife left me to organize nuts and bolts...and it fit! Taped it in place, and drilled a hole wuth a grommet on the bottom with strain relief for the cables.

I soldered in very long and sturdy red and black wires for teh switched power and ground for the unit. I had previously installed spare switched power and grounds on a panel in the engine compartment so it is plug-and-play.

I installed it all and took the car for a spin around the block, making notes as I went. It wasnt too lean anywhere but I noted needed some more initial accelerator-pump on throttle tip-in.

THe real revelation though was when I got the car back to home all warmed up and noticed the AFRs at idle were 17-19!

I started with teh 123 bank where the O2 sensor was installed in the collector. I had adjusted the sync and linkage already. I then was able to adjust each cylinder's mixture by letting out each mixture screw in turn and noting the change in AFRs. Let them out one at a time until it richened slightly, dial back a bit and repeat through the bank,. I have O2 bungs in both collectors so I switched the sensor over to the other side and repeated. As with t123 side, I was idling ~17 AFR. Richening it up and resetting idle speed got it all dialed in.


What a useful tool!

[JohnJL]

The pics dont capture the LED well at all, it is bright and fast. I can also log it...

[Hi_Fi_Guy]

Bravo!

[JohnJL]

Pics didnt post, trying again...