Diagnostics Doctor
Your diagnostics-related problems sorted.
QI have owned a 1999 Land Rover Defender Td5 for 14 years with 54,000 miles from new. It has no immobiliser. It broke down with no warning misfiring or spluttering, just cutout and would not start. Recovery was called and the mechanic connected his diagnostic tester which showed up 20 faults. Top of the list was ABS, which it has not got, next was injectors and fuel pump. He deleted them all, tested it again and they all come back. Also made several attempts to start the vehicle. After been towed home on a fixed bar, he thought it could be fuel pump or possible injector loom.
The following is what I have done since. Replaced injector loom – no oil contamination on the wiring or back to the ECU. The old loom looked excellent but renewed it as it was the original. Can hear the fuel pump make it usual noise. Can still initiate the bleeding sequence, so I connected a pressure gauge on the high-pressure side and got 4 bar pressure and pumped 200ml in five seconds. I read somewhere a faulty crank sensor was one of the few things to bring the engine to a stop, so I renewed that, checking the wiring for continuity back to the ECU. Checked the main earths which showed no resistance (just learning to use a multimeter!) Checkedout the ignition switch terminals, all show live at the correct time. The battery is excellent and spins the engine over well.
Have not touched the pressure regulator on the basis that it would not stop the engine from starting (online info). Changed small return valve in the filter housing, again online advice. After each of the above individual procedures it still would not start. Removed the lid of the ECU – it looked prefect, no burns, smells or oil.
I have not got a diagnostic tool but can hire a Nanacom dedicated Land Rover one if you think this might help sort out the problem. If you think the ECU needs checking out can you recommend a company I can send it too.
Many thanks for any input you can give. Michael Bone
AA sudden and terminal stop which is accompanied by a plethora of codes, which do not clear, does suggest that the fault may be in the ECU, or the earth system. The injector harness is certainly a problem on these engines and this is a point you have also covered, along with the crankshaft sensor which could also have been the culprit.
With these possibilities out of the way I would strongly expect the ECU to be the source of the problem, the symptoms you have of cutting-out, failure to start and the multiple codes which fail to clear and appear to be unrelated are all indications of an ECU failure.
I would send this off to one of the companies that can perform the test and repair as required. ecutesting.com and bba-reman.com are both very capable of this.
As the codes have already been read and an attempt to clear them has been made, I believe that to have the ECU tested would be a better option at this stage than hiring a diagnostic tool.