WTB ECU 1990 RR Classic 3.9

[NC_Mule]

Back tracking a no spark issue. My mechanic believes it's at the ECU. Does anyone have a used ECU from a running RRC to sell?
I believe this ignition only has advance no retard function.
Thank you.

[mearstrae]

You have a "14CUX" ECU. Pretty much any Range Rover or Discovery 14CUX ECU should work from 1990 to 1995 (they have numbers like: PRC-7081 or 8742 or 9060). Check the passenger side under seat on board code reader, you'll probably have to take the bottom trim off the seat to see it, it faces the door. The number codes read out one at a time, so clear one and move on to the next. You will have to find an on-line source to translate these into English. Hope this helps...

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S

As a second thought... Did you check your Lucas electronic module in the distributor? They as famous for failure.

[phoenix]

Ecu has nothing to do with spark, spark controls injector pulse thru ecu. ecus are bullet proof, I had sunken those things in muddy water, removed and rinse with clean bottled water, dried with napkins and on board compressed air and kept on running.

[NC_Mule]

Thanks for the reply. A friend has had his RRC at 2 shops for months at each. The first shop is a good import car shop the second is a long standing independent Land Rover shop. No one can get the spark plugs to fire. Last I heard a new ignition switch was going in. I think they wanted to swap ECU's just to rule it out.

I'll post the fix when it happens.

pb

[mearstrae]

Another thing I just remembered is that there is a 'White' wire on the ignition coil that allows the fuel injection to work. If it's not connected the vehicle will start and then die in a few seconds, this is to prevent an over rich condition in case of starting failure.

'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III Hybrid 109
'70 Rover 3500S

[MJL]

I think the white wire you are referring to is the lead from the coil to the ECU. If memory serves me correctly this supplies a signal to the ECU to let it know that the engine is cranking. If it doesn't get this signal it will not supply power to the injectors so you actually have a no fuel condition. The lead in question has a 6.8K ohm resistor in it the connectors of which can get severely corroded. The resistor is wrapped up in the wiring harness that is close to the mass air flow unit. Just follow the lead from the coil (I think it's actually white/black) and unwrap the harness and you will see what I mean. The resistor is a small rectangular black thing with a spade connector at each end. To test you can just by-pass the resistor by unplugging both connector and joining them together. If it works you should replace the resistor - I just bought one at Radio Shack and soldered in the circuit as I couldn't find a source for the original. It's about 14 years or more since I diagnosed this on one of my RR's (unfortunately long gone).