Wath does fuel failure means on a 1988 jaguar xj6

it should be on the rear suspension a frame at the lhs

THE COSE MEANS YOU PUT THE WRONG FIRING ORDER ON THE CAP OR THE SPACE BETWEEN THE SPARK PLUGS ARE WRONGTHE FIRING ORDER IS 153624 AND THE SPACE BETWEEN THE SPARK PLUGS IS .035

where is fuel relay located on 1988 jaguar xj6

The fuel pump is in the gas tank.

I've heard this could be an O2 or "lambda" sensor failure.

there is a release lever in the trunk beneath the gas cover you can push to release

That means there is a problem with the oxygen sensor that is fitted in the exhaust

try e mailing the jaguar owners club in the uk.they are all petrolheads......

Fuel pump is bad or plugged fuel filter it seems. Crack the line from the filter leading towards the engine first. If gas starts squirting out fast, you have good pressue. If not the filter is plugged or a bad pump. How old is the fuel filter by chance? If original its plugged up by now

I to have a 1988 Daimler 3.6 vanden plas. I would greatley appreciate if some one could let me know about any information on this model, ie; what made the vdp different from the standard daimler 3.6, production numbers and origional cost. In regards to your question, my daimler also said it had fuel failure. I put some injector cleaner in with the petrol and the warning hasnt come up since. As for the circuit 2 failure, it could be numerous things, but start with checking the fuses in the left side fuse box. It could also mean that a light bulb or other elecrical item has a broken circuit somewhere.