xjs 40l ff23

[allan1955]

hi any help 1993 xjs 40l engine management code ff 23 thank allan

[MARKPEARSON]

Hello Allan.
FF 23 refers to the fuel supply fuelling rich.Lambda sensor error - fueling rich. Feedback signal high despite correcting weak by more than 12.5%.
I personally would start by getting the lambda sensor checked first.Either at independent Jaguar specialist or specialist or local garage who specialises in auto electronics such as bosch service center.

Hope this helps regards Mark. 1993 4.0

ps you coule e mail David Marks I am sure he will point you in the right direction.

[almcl]

I had this fault code a lot with my previous 4.0 ltr.

It was nearly always a transient. Invariably, resetting the system cleared it.

I bought a replacement sensor and put it in the glove box, just in case. Shortly after that the fault stopped occurring.

Is yours transient (ie resettable) or is it continuous?

[MARKPEARSON]

Good point you can keep resetting fault code but the next mot test will reveal if there is a fault or not if the car fails the emission test or passes it.
If you go down this route and it does fail mot on emissions get lambda checked many a mot test station has diagnosed high emissions on catalyser failiure when cat is ok.At least this saves expense of getting lambda tested.

Regards Mark.

[allan1955]

many thank to all allan

[nigel1]

I had this problem over a 2 year period, tried all sorts of remedies, replaced the lambda sensor, removed and cleaned the purge valve, cleaned the injectors, fault remained intermitantly.
Then, one day while checking the wiring loom (the one strapped to the fuel rail, as this has been reported as a cause due to poor connections), I happened to move the wires from the water temp sender and this caused the engine revs to fluctuate, and then go horribly rough, and engine died, triggering a temp sender fault. Tried again and noted that the revs varied as the temp senders wires were moved closer to the TPS loom.
I cable tied the temp sender wires to keep well clear of the TPS wires, and since that day, and 4 years later, no re-occurance of FF23.
So, I would try giving the wires a good shake as the engine is running and see if that causes the FF23 to flag. Also, check that engine and ECU grounds are in good condition