Poor Fuel Economy...Sometimes

[sbobev (Steve)]

@Kirbert

That’s from Bywater, I only relayed it. And it’s not only just the 3.6, it’s just

the EARLY 3.6, the one with an 8CU ECU. It responds exactly the wrong

way to engine wear, so a worn but still serviceable engine runs so badly it’s

inoperable. Bywater offers a fix that involves an added trim pot on the ECU.

A more likely issue here is that the oxygen sensor heaters aren’t working for

some reason, perhaps the power to them is faulty or the sensors themselves

are faulty. WIthout heat, the sensors will work sometimes – and many

report that non-working sensors play havoc with the fuel economy.

I have been in contact with him, and he refurbished the second 36CU for me – custom fuel map. No change.

As of the 02-sensors – I am on my 4th or 5th pair. Have tried every brand (non-brand) out there. No change. And have tested for voltage the heater wires. There is power. What are the chances that so many O2-sensors have inop heaters?

Steve

PS This is over the course of 7 years and less than 15,000 miles.

EDIT:
Most of my posts are still in the archives, but somewhat hard to retrieve. This one is where we covered the way the 36CU re-adapts

[xj-s] Adaptive idle fueling trim ...?

Gentlemen: The text below is taken verbatim from the JDHT for the 6.0L. I have read and re-read multiple times, but have to admit – I have no idea what they are trying to say. Apologies for the ‘dumb’ question, but would someone be able to provide the explanation in layman terms?— Adaptive idle fueling trim In order to ensure optimum performance throughout the life of the vehicle, the fuel injection ECM software contains an adaptive idle fueling function that automatically trims the fu…