Help with my 1995 Range Rover Classic 4.2L

Hi all.

I have recently had problem with my 1995 Range Rover Classic 4.2L LWB.
For some reason it wouldn't start so I took it to mechanic. He checked the fuel pressure, which was ok, then he checked the fuel injector relays under the dash of passenger side, he replaced one of relays, and finally he checked the fuses under hood, and 15A fuse was burned out. After replacing fuse the Rangie came back to life. But what happened next was that the idling would be unstable, jumping up and down, you could smell that the fuel was running rich, and fuel consumption increased by 50%. Also the truck lost his power while accelerating.
I would appreciate if anyone of gurus could list the possible causes of:
1.Cause of increasing of fuel consumption
2.Why engine is running rich
3.Unstable idling.
4.Loss of engine's power
Any input would be greatly appreciated.
Cheers.
Arsene.

Take off and clean your stepper motor (idle stabilisation valve). Take off and clean the plenum and ram housing. Check the setting of your MAF, check and set your base idle, check the ignition timing and make sure the vac advance and mechanical advance are both working.

OOPs! not sure '95 engines had dizzy, if serpentine then would be different.

Check stepper and MAF, clean plenum etc see what happens.

One other thought, check the oxygen sensors (lambda sensors) on the exhaust.