I am presuming you are dealing with a 94/95 Disco I since it doesn't sound like you are OBDII. You say it won't turn over, but I am going to assume it turns over, but just doesn't fire.
If you were running rich you may have melted the CATs this will cause the engine not to run as well. Have you checked spark?
Way too late just running across this thread.
JMO i'd check the fuel rail pressure port to find out if the fuel pressure regulator had failed as well what the rail pressure reading was?
Running rough plus rich is a clue the pressure regulator is at fault which should read a pressure of 2.5 Bars (36.75 psi)
Even brand new for your Disco these 2.5 Bar regulators will go into bypass the pressures nearing and at the minimum pressure spec psi numbers.
The 94 & 95 only (OB1) U.S. North American Market Discos the pressure regulator is bolted up to the fuel rail with a ****** at the inlet side for the rubber flex hose connection.
Do yourself a favor and install a late 80's era BMW fuel pressure regulator which is identical physically with a 3.0 Bar bypass.
The 87 325 is BMW's 3.0 Bar (same physically as the Disco's 2.5 Bar) regulator went to bypass at 107 psi hence running rich, too rich beyond the BMW's ECM able to shorten the injector's pulse. Car purchased at a massive discount, yes it destroyed (melted) the Cat. a ($87) Magna Flow universal replacement Cat approved for California years ago.
The 3.0 Bar regulator bypasses around 1.6 to 2.2 psi above LR's Disco factory max spec numbers.
Higher pressures allow for stronger Lucas single port dribble injectors a 1980's design. Better yet running 4-hole Bosch injectors allowing finer fuel spray patterns allowing for finer
fuel particles to vaporize hence a better combustion burn also cleaner smog check reading numbers. This after testing and selecting injectors a set of eight flowing within 0.75% of flows (simulated 450 rpm idle) to 95% duty cycle (simulated 8,200 rpm's pulser) injectors. (Racing within 1.00% flow bac of eight injectors). Spray patterns also checked a 15* (degree fan width 4-hole spray pattern) aimed at the backside of the intake valves and not the head port walls.
I own a Sun Investigator Smog Machine passing smog "Too Clean" ere in California with a 4.8 litre with the Mark Adams chip.
Best for all members to find your issue and posting to help other Disco owners......PROST......~~=o&o>.......
