At the moment I'm working on the installation of the ProECU-K in my Lotus Elise and I'm intending to use an external wideband controller (with a PRA ECU).
All vendors of such controllers put in their installation instructions that you should only turn on the controller, and in effect the heater of the sensor, after the engine has been started to reduce the risk of condensation droplets causing thermal shock and damaging or breaking the sensor element.
I will be using an LSU4.9 sensor which is not as susceptible as the LSU4.2, but it's still good advice.
For my purpose I will probably put the main power feed to my wideband controller behind a small time-delay relay which is triggered by the fuel pump output on the ECU so it will only turn on after the fuel pump has been running for at least 30 seconds continuously (so it won't turn on right after the initial 2 second fuel pump prime)
The controller and wideband should then be ready for data in about 30 seconds, so after about 60-90 seconds the signal should be usable by the ECU which is configurable in the ProECU software.
I'm building a new cover plate for the ECU which will house the wideband controller as well as the relay(s) anf fuses and the ProECU expansion box so it's all a nice single package with as little external wiring mess as possible.
For me this should work fine, but I'm curious what other people have been using for this and their experiences on reliability of their solutions. I can imagine some other solutions like using:
- A simple manual switch
- A specific output from the ECU to trigger the relay (eg. A/C out), but not that many on a PRA ECU and I want to use that to switch an exhaust valve..
- An external rpm signal trigger circuit that enables a relay if the rpm signal exceeds >500rpm for a certain time
etc. etc. etc..