| Author | Message | ||
     Degart Kilroy (Degart) New Member Username: Degart Post Number: 1 Registered: 10-2003 |
I am wondering if you guys could provide me with some assistance. I own a 2003 Land Rover Discovery engineered to U.S. specifications. This includes a 4.6-liter High Compression unleaded petrol engine. Type: 90-degree V8 Construction: Cast aluminum-alloy cylinder head and block. Dry steel cylinder liners. Cross-bolted main bearings Displacement: 4.6 litres (278 cu. In./4554 cu. Cm) Bore x stroke: 3.70 x 3.20 in. (94 x 81 mm) Compression ratio: 9.35:1 Engine management: Bosch Motronic 5.2.1 Ignition: Distributorless ignition system. Dual knock sensors. Fuel requirements: Premium unleaded Fuel Tank: 24.6 U.S. gallons (93 litres) I would like to export the vehicle to Africa. The only petrol available in most countries in Africa is leaded. As I am sure you are aware, the lead will ruin the vehicles O2 sensors, and catalytic converters. I can have the sensors and converters removed, however, I am told that this would cause confusion within the engine management system that would lead to wrong air/fuel ratios, spark retardation, and various other negative issues. My questions is do you know if I can purchase a new ECU or have my existing ECU reprogrammed to account for the engine not having catalytic converters and O2 sensors? If so, where? | ||
| Degart Kilroy (Degart) New Member Username: Degart Post Number: 2 Registered: 10-2003 |
More information I have found: On NAS vehicles the ECM also monitors the efficiency of the catalysts. The ECM uses the signal received from the two post-catalyst Oxygen sensors to do this. The state of each catalyst is assessed in line with its ability to ‘hold’ Oxygen. In a serviceable unit the ‘excess’ Oxygen in the exhaust gas is held on the surface of the precious metal coating of the ceramic blocks within the catalyst. This Oxygen is used to convert the harmful elements produced by incomplete combustion (particularly during acceleration and conditions where the engine requires a rich air/fuel ratio) into Carbon Dioxide, Nitrogen and water. By comparing the signals received from the pre-catalyst sensors with those received from the post-catalyst sensors, the ECM can calculate how much Oxygen is retained by each catalyst and can, therefore, determine their condition. If the ECM determines that one or both catalysts require replacement, then it will illuminate the MIL lamp (after debouncing the fault) and store the relevant fault code. At the same time, the ECM will record details of the engine speed, engine load and air temperature. The ECM requires the Oxygen sensor signals to set most of its adaptations. Failure of an Oxygen sensor will result in most of these adaptations resetting to their default values. This, in turn, will result in the engine losing its ‘finesse’. The engine may exhibit poor idle characteristics and emit a strong smell of rotten eggs from the exhaust (H2S). |
