Enigmatic 3.2JTS

Started by Ascari32, November 09, 2020, 09:51:45 PM

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As a foot note to my previous, I left the battery off the car overnight, to discover whether, or not, the fault codes would reset.

The answer being no!

However, on reconnecting the battery, the MAF output signal is recalibrated to ensure the metering is precisely as dictated by the ECU maps. I make the broad assumption, this parameter is set to within a predetermined range. So, on restarting the engine, the car refused to idle and continually died; hiccupping is the best way to describe it.

Dynamically; when neither the battery has been removed or the ECU reset, it seems with the resistor in circuit the ECU can adjust. But, when recalibrating after  re - fitting the battery or resetting the ECU, it cannot.

Removing the 600 ohm resistor from the loop and absolutely fine, slightly over - rich but ticking over with a healthy exhaust note. However, simply putting the resistor back in circuit afterwards, everything is restored to what it was before the battery was removed or the ECU reset. 

Clearly this is an issue I cannot resolve without software modification. However, that is something I am vehemently against. The intention was never to go down that route, if at all possible. So my solution is to always reset the MAF loop to factory standard, by fitting a switch to bypass any resistor network I finally settle for: when the new MAF element arrives.

Essentially, whenever the battery is disconnected or fault codes are cleared through the OBD Port, the network will have to be switched out. But I don't see that as a major drawback, particularly if it permits me to find the optimum position on the MAF characteristic. A third position on a switch could also be used to inhibit the engine from starting; an anti-theft device.

I would like to think, this finally brings to an end the rebuild work on my Brera engine which is installed in my 159. I can't think there are any more issues, but one never knows. Now, I think it is time to spend a bit of time sprucing her up and simply having some fun.

But there again, there could be another project on the horizon!