FF23

[rsims193141]

On my 1992 , 4L, manual,on turning the engine on the readout on the radio says check engine FF23,any idea what it is,or where i could find out.

[cafcpete]

Have a look here, it gives a list of things to try.
https://forums.jag-lovers.com/t/1993-xj ... f23/354476

This is a link to the diagnostic guide that was mentioned
http://www.jagrepair.com/images/AutoRep ... %20S91.pdf

[AndyF]

I had a FF23 issue on my V12, see the forum entry in the engine section. I found many minor issues with mine, and along with a big dose of preventative maintenance, made a difference. The biggest breakthrough, however, was the fitment by Dave Marks of improved earthing to both banks of cylinders.

My recommendation would be to work through the list of points from the Jaglovers page for the AJ6 systematically. Please let us know how you get on!

Good luck.

AndyF

[almcl]

Maybe worth mentioning that if the code is displayed without the check engine light illuminating, then it's a stored code, and the fault which caused it may not still be present.

It's been a while since I had this fault (20 years, in fact) but I think it was cleared by disconnecting the battery for a few minutes. If it then comes back (the check engine warning light will illuminate) the fault is still present. If it stays away, then it was perhaps a transient.