Hi,
I have a FZJ75RP 4.5 petrol. It is currently getting around 28-30 litres per 100k’s. So far I’m pointing towards the timing being the issue, being that the ECU retards the timing if it can’t keep within its set parameters. I’m not sure whether to replace knock sensors or the ECU? I know the ECU only works with the signals it gets from sensors on and around the engine so if there’s a bung sensor the ECU is probably fine. I have recently changed the engine temp sensor as that was another one that I have heard of to mess around with the ECU/fuel economy.
When I disconnect the battery for 5 mins, enough to reset the ECU and wipe it’s “learn mode”, it seems to have its driveability back but not for long until I’m guessing, the timing is retarded again by the ECU.
I have checked all the basics first; spark plugs, air cleaner, exhaust, fuel, drivetrain (wheel bearings, wheel free spin, etc.). I have also checked the timing (bridging E1 and TE1 whichever they are) and it is bang on 3degrees. There are no EFI fault codes either. All these factors are making me believe it is the ECU retarding the timing enough to get it into its “safe mode”.
I really want to get this fuel/power loss issue sorted as I don’t want to sell it. If anyone has any ideas, or some ways I can test to eliminate some probable causes I would be greatly appreciated.
Regards,
Daniel
I have a FZJ75RP 4.5 petrol. It is currently getting around 28-30 litres per 100k’s. So far I’m pointing towards the timing being the issue, being that the ECU retards the timing if it can’t keep within its set parameters. I’m not sure whether to replace knock sensors or the ECU? I know the ECU only works with the signals it gets from sensors on and around the engine so if there’s a bung sensor the ECU is probably fine. I have recently changed the engine temp sensor as that was another one that I have heard of to mess around with the ECU/fuel economy.
When I disconnect the battery for 5 mins, enough to reset the ECU and wipe it’s “learn mode”, it seems to have its driveability back but not for long until I’m guessing, the timing is retarded again by the ECU.
I have checked all the basics first; spark plugs, air cleaner, exhaust, fuel, drivetrain (wheel bearings, wheel free spin, etc.). I have also checked the timing (bridging E1 and TE1 whichever they are) and it is bang on 3degrees. There are no EFI fault codes either. All these factors are making me believe it is the ECU retarding the timing enough to get it into its “safe mode”.
I really want to get this fuel/power loss issue sorted as I don’t want to sell it. If anyone has any ideas, or some ways I can test to eliminate some probable causes I would be greatly appreciated.
Regards,
Daniel