Hi
Sorry, this is long.....
A long time ago I bought what I thought would be a useful AEM air fuel ratio kit (called X WiFi kit). Unlike most normal AFR kits with a dial and sensor this was a black box and a sensor for the exhaust and you attached to the box via a phone or IPad etc using WIFI. The kit was produced in the mid/late 2000s however I only managed to get it to work with a very old iPad 2 which is now defunct. I had a boss installed in the exhaust when building the car and did run it to test originally when I first put the car on the road. Cannot remember the values, but seemed sensible from memory.
Moving on to now, I had been conscious of the exhaust always being very black at the exit and on checking the plugs they were very black and sooty. Some of that would be recent moving the car around the drive exch day to keep the sun off, but thinking that something was amiss, I decided to check everything. I have had the carb off reasonably recently to check all was ok with the passageways, so did not venture ther, but did adjust the float level a bit lower as it appeared it to point towards the lid when the lid was upside down. I adjusted it so it was approx sitting level.
Another thought I had which was prompted by one of the writers in an old Classic Car mag was if the fuel pump was building up too much pressure and overwhelming the inlet valve of the carb. After a couple of wrong purchases I had a pressure gauge in the line which showed no appreciable back pressure to the carb from the mechanical pump as you would expect with the return line.
So I decided to put the AFR kit back into car, but had to work out how and on what to get the kit to show the readings. Reading through the docs, I noted that you could attach a USB cable and there was an old application for Windows available for download on the AEM site. So duly downloaded and tried to install on a Windows 10 box, first problem was the installer needs Microsoft .Net Framework V2, which is pretty ancient, after some searching I found a V2 .Net installer then managed to install the AEM app. On running it it came up first time and on connecting the USB to the powered up black box it installed a serial COM port driver. You then need to select that com port in the AEM app and connect, that was when a non sensible error came up which meant I could go no further.
So back to square one, however thinking that era of the kit was earlier Windows, I fired up an old version of XP which I have used for donkeys years, went through the same procedure and hey presto it all worked and I had a continuous readout of the sensor.
Next job was to semi permanently install the sensor/wiring/black box into the car. This was fairly simple and easy enough to remove. The black box is in the engine bay so how to get the usb from the cabin area. Fortunately on the pre facelift the side vents are direct into the scuttle, so a bit of thinning of the USB connector plastic and it fed through the vent and routed to the black box.
After a decent run I found that the normal AFR reading is around 13.1 which according to what I have read is very much ok for NA cars and on removing a plug the colour is also a nice brownish colour rather than the black previously seen.
I will keep monitoring it, but pretty happy with the results.
On a final note I also did a compression test when cold and all cylinders were at 150PSI which is what I had found originally when I put the car back on the road in 2021.
Peter
