Today I replaced the aftermarket fuel filter I fitted last year, with an OE filter, as apparently the cheap aftermarket filters can cause hot running REDUCED POWER issues on the dash, and sometimes allow air to enter the fuel feed to the fuel pumps.
I didn't notice any power issues when hot, but I definitely was getting air into the fuel line, which I believe is giving the random throttle induced misfire, especially when cold.
So I figured I'd eliminate the filter first, by fitting a filter with "Purflux" on the top, as this is definitely an OE part.
It's a fiddly and messy job, which inevitably results in fuel spillage over the old and new filter.
Annoyingly replacing the filter didn't solve the air in the fuel line either, so I started looking at other potential routes for air to enter the system.
The only place where air can enter (the fuel pipe is under vacuum), is at the joint where the filter is connected to the fuel outlet to the pumps. So I decided I'd change the O rings in the QR fitting.
I carefully removed the O rings from the intake side of the filter I'd just removed, and also carefully pulled the engine side
fuel feed fitting apart (it's also the fuel temperature sensor too), and swapped the O rings over, going on the theory the O rings from the old filter are 12 years younger than the O rings in the fuel line.
Here's the old O rings, the new ones are fitted in the connector/temp sensor (marked with a red line.
The good news is there seems to be less air in the system, after a quick rev I couldn't see any more large bubbles, just tiny bubbles, which I'm guessing will clear as the fuel is drawn though.
I'll give it a good run tomorrow, and I also want to put SDD on it, to reset the adaptations, and also do a complete air path calibration, which hasn't been done with the new head fitted.
I'm hoping that once done, it'll run even better, at which point I can move on to the Haldex grabbing issue. You gotta love these more complex Freelanders, but I do wonder if they're just a bit too complex for their own good.