95 Range Rover Classic Code 12

[bainbridgebob]

Voltage check showed 3 volts pins 3 to 6 on connector instead of 4, but replaced air flow sensor anyway. no change in rough running engine. Found engine ecu, I think, tucked up above footwell, pass. side but it is not clear how to get the connector off let alone open the cover so I can probe the back side. Any suggestions re the low voltage reading and how to access the ecu would be appreciated (The manuals I purchased have electrical troubleshooting through 94. It appears that in 95 several things changed that are not captured in the manuals for the 95 classic) Thanks for your suggestions

 

[joey]

You haven't given us much info other than the Code 12 which does normally indicate the MAF sensor.

When was the last major tune up? What plugs are you using? Did you change the Wires?

Fuel filter?

Mileage?

When did the issue start? Recent work around that time, including if you changed the radio or speakers?

Have you cleaned the intake at the butterfly?

 

[bainbridgebob]

95 Range Rover Classic

Thank you, Joey. I just bought the car and the service records are not complete. I replaced the plugs with NGK BPR5EY as well as the distributer cap and ignition wires. The car was almost impossible to start after washing the engine. The airflow meter was very dirty and I cleaned the sensor wires with electrical contact cleaner. --no change so I replaced it. The butterfly valve has some oil deposits but I was not sure how to best clean them off. Since the air flow meter was dirty I imagine that there are deposits in the intake manifold also.The injectors were cleaned in 05 at 75,000 miles and the fuel tank replaced about the same time. No mention of fuel filter.The car has 103,000 miles. I doubt that it has had tune up recently since there are no Rover dealers in Bellingham where it has lived for 5 years. A local mechanic who attempted to fix a small water leak apparently at the thermostat housing noted that the car was running very rich. (A can of radiator stop leak fixed the leak for now)

 

[joey]

I am sure you will hear otherwise, but my preference is Cheap Champion plugs they seem to work best. Distributor cap, do you remember if it was a lucas cap? If not find one.

Butterfly valve I normally just use some intake/injector cleaner and a rag.

Poor idle can also come from the TPS (throttle position sensor) and the IAC (Idle Air Control).

Fuel filter I would change ASAP since it can cause other major issues if not replaced (i.e. cause the fuel pump to go bad.)

If hard to start after a wash it could be the distributor cap...

 

[bainbridgebob]

I reset the code after finding the ECU. The 12 went away and the car runs better. But, the check engine light came on after a minute, this time with no codes displayed. (It is a Lucas distributor cap. I'll work on the fuel filter next.) Thanks for your suggestions