The V8 Owners Forum -

Just had the MOT done passed no problem. Tested on LPG CO2 0.047% and HC 62ppm.

Getting to serious despair time, just can't find what's wrong with this setup. We have replaced all four 02 sensors, throttle position sensor, Engine Coolant Sensor, MAF and the ECU, checked for air leaks etc to no avail. I don't know if this says anything to anyone: https://lh5.googleusercontent.co...

Yep. Start up went to 1248rpm. Pre-cat sensors climbed quickly to 0.900vs and held around that. The engine temp reached 76 degrees after 5 minutes then the post-cat sensors went from 0.454 to around 0.900. As before (when it was reading lean) revving the engine induced short periods of switching, en...

OK, now I am very confused the diagnostics done on Saturday revealed a consistent lean reading from the sensors which went rich if I restricted the air flow and flipped a bit after raising the revs. Now it's showing constantly rich, and will only go lean if you increase the air flow (removed the oil...

The four brown wires are the live feeds from fuse 2 for the heaters

Therein lies the problem, no black wires:

They are 4 wire, the wiring diagrams are a bit unclear as to how they are earthed.

Cheers

Bill

So the ECU was not at fault so back to square 1. The motor won't go closed loop and the O2 sensors were almost constantly sending a lean signal back to the ECU. I found a molten but not blown fuse that covers the feed to the heater circuit on the sensors, but as yet found no cause, after replacing t...

Never got mine back from Lynx so we managed to source a new one for £170, didn't solve the problem, please see my new thread.

A word of warning, I would advise anyone needing ECU work done to avoid Lynx, I have just listened to a telephone conversation between them and my garage and basically their customer service is none existent, it will be done when it's done and we are idiots for trying run a 4.6 engine with a 4.0 ECU...

Back again. Right the ECU went of to Lynx Automotive for repair which is where it's been for the best part of 4 weeks, they are proving a pain in the arse, not really telling us anything just keep saying it's a complex repair maybe next week, not very happy. Anyone know anything about them? Thinking...

Surely if the cats have gone, the power delivery problem would be at all revs? and power overall doesn't seem effected, if I plant my foot to the floor she takes off like scalded cat.

What are the symptoms for failed cats any way to test them?

All sensors have been individually checked and appear to be functioning correctly. We tried swapping ECUs but despite mine having the factory immobiliser deactivated, neither ECU will run the other vehicle, which is puzzling. We have compared the ECU readouts between two motors and everything is nea...

Cheers guys,

Cats no idea but at least 2 years that's how long I have had it.

Mine has had the immobiliser deactivated (got an after-market one) so we are going to try an put mine into the garage's V8.

What are the symptoms of a failed ECU? I have a Discovery II with a recon 4.6 on it's original 4.0 ECU, it ran fine for 1200 miles and then developed a hesitancy around 1750 revs under low acceleration and fuel consumption gradually fell away. Initially there were no fault codes and we found a damag...