I recently bought a 1984 Alfa GTV6 and a previous owner had custom stainless exhaust built from the manifolds back, but didn't put in any provision for an oxygen sensor. The connector for the sensor is just dangling in the engine bay, and the car runs open loop all the time, which is less than ideal. The factory EFI is Bosch L-Jetronic.
A number of other observations (aftermarket adjustable FPR, signs of tampering with the AFM) have my spidey senses tingling about someone attempting dated "performance" hacks that have done goodness knows what to actual air-to-fuel ratios. It runs, but idle is erratic, and seems quite rich, and I've had a couple brief high-rpm, high-load rough-running experiences that have me terrified it could be going lean in those conditions.
I need:
- A sensor that can provide an appropriate signal for the factory EFI to run closed loop
- A bung in the exhaust for said sensor
- A way to monitor AFRs while I sort through the rest of the system and get it sorted
It seems to me that a wideband sensor, controller, and gauge could be the way to achieve all of this, provided it has an output that can be configured to emulate a narrowband output for the L-Jetronic, which I think is looking for a lambda sensor that outputs 0.1V to 0.9v if my Googling is correct.
The last time I researched and purchased a setup like this was 10 years ago, and it was for carbed motorcycle tuning. I think I got either an AEM UEGO or an Innovate LC-something, and purchased the gauge separately, but I can't recall exactly what led to that decision.
What's the hot ticket these days if quality and ease of setup are primary considerations, and cost is not as much of a concern? Logging capability and a retro-looking black gauge face are nice bonuses, but not required.
Thanks in advance for any input.
The AEM units are far better than Innovate.
One thing that people talked about doing with Bosch systems (KE-jet in this case) was using a wideband controller that could do a narrowband emulation, and also had a programmable output wire. The thing was, you configure this second wire to emulate a narrowband signal with a switchpoint at your preferred WOT ratio (say, 13:1), then wire the sensor output through a relay with the 30 pin as output to the computer, 87A to the one signal and 87 to the other. The WOT switch is disconnected from the computer and instead switches this relay.
Voila, you now have closed loop operation even at WOT.
I do remember the Innovate LC-series having that capability...check out page 8 of the manual, it should be able to do what you want but it will need to be programmed to suit:
https://www.innovatemotorsports.com/lc-2-complete-lambda-cable-kit-8-ft.html
In reply to Pete. (l33t FS) :
Clever! See...this type of brilliance is why I love this place! Thanks for the suggestion. 
It would be interesting to see some data when you are done. Most cars of that era would not learn the exhaust to alter the WOT fuel, so you should be able to run closed loop when intended and not change the power fuel.
Meaning tune the closed loop fuel to run well and get decent fuel economy (no need to run too rich to waste fuel). And then WOT can be for peak power.
I ordered an AEM gauge/controller. The "classic" one with the analog-looking face with digital readout in the middle. It will still stick out in the interior with all the Veglia instruments, but hopefully won't be a massive sore thumb with the black face and black bezel. Comes with a Bosch sensor, and can be calibrated to output the Nernst cell 0.1V to 0.9V lambda signal to the stock ECU. It can also be used for logging. Thanks for the input. I'll let you know how things develop.
Will be interesting what you find. I'm with Alfa on this one, likely fiddling with things open loop will not have much impact on the closed loop unless things are way out of wack. I did some similat things with my cis-lambda rabbit back in the early 00s with a techedge wideband. Worked out well actually seeing afr data.
In reply to ae86andkp61 (Forum Supporter) :
Please be safe and lean heavier on the data logging aspect of the system. The time where you can look at the sensor and take it in is very limited in running time.
