4.6 conversion problems

Well if I wasn't confused before I am now. Just ran the diagnostics again, this time she is showing constant high voltage - rich, doubled checked this by removing the oil filler cap, went to from >0.8 to >0.1 as you would expect by adding more air, the only thing I can see that is different is the air temperature!

This is getting better actually.

If the mixture had been made rich by the fuel trims being altered, then they could go rich.

This could be an airleak relating to a crankcase ventillation pipes or valves. PCV valves are designed to control the airflow through the crankcase.

If the pipe is cracked badly, or the valve is sticking, the expected level of ventillation will not be achieved.

With crankcase ventillation systems, many are designed to bypass the throttle body/throttle valve, which could act as a significant airleak making the engine run leaner than normal, especially if the rubber pipe is leaking.

It depends where the crankcase inlet is positioned with respect to the airflow meter.

If the inlet is before the airflow meter, then the airflow meter won't know anything about it, but if it is after the airflow meter, then it should be compensated for very easily, but if the fuel map is based around the throttle position sensor data, it might start to change the data at each throttle position data point.

Of course I am not familiar with all of this ECU map stuff on the LR system, but I am sure that there are some who could fill in the relevant gaps and tell us what the system would do.

I've actually been having a problem on another vehicle, and you have actually prompted me to look at that part of it, but on mine, everything was renewed. Might block mine off for a bit as it might be a resonance problem on mine, yup, it is that type of wierd problem.

Still can't find any wiring problems, but may have found another straw to clutch at, cats! I have been mainly concentrating on the pre-cat 02 sensor readings as they control the fuelling, but having looked at the post cat sensors, I note that instead of reading around .45v as they should they are mirroring the pre-cat readings am I right in that this is indicative of cat problems and could they be the cause of my woes?

Sensor Readings
All sensors started at 0.45 after 20 seconds or so the pre-cats rose to 0.765 or thereabouts, revving induced some switching mainly in bank 2, when engine temp reached 80 degrees the post-cat sensors rose to around 0.760 as well. Revving to around 1600 revs induced some degree of flipping on bank 2 pre-cat sensor but towards the lean end and the post-cat sensor went lean with much less a range of flipping, back to idle and everything went rich again, lifted the revs and the same thing happened.

Cheers

Bill

Well not sure what this says, but disconnected the front 02 sensors and instead of showing Open Loop Fault, she is now showing as just Open Loop. The rear lambdas went rich at 80 degrees or thereabouts again.

Did a short run today with the front 02 sensors disconnected, so I am assuming running the default fuel map and although she felt a bit livelier I am not convinced she is running any better. One thing I noticed was when I switched to gas, the hesitation took a while to become apparent but its still there.

I am wondering whether the hesitation and the not going closed loop/running lean/rich on petrol are related or not or would running lean on gas produce much more pronounced symptoms than on petrol.

Gas will always show up a compression or weak spark condition on a engine
As petrol is a more flammable fuel it will not be quite as pronounced
Another issue could be a fault with the valve train still feel it could be a mechanical issue rather than electrical as all was running fine before the engine swap any more news on the mechanical spec?

Sorry Stu forgot to say all B+H had to say re the engine parts used are that they are all either original parts or better. Just a point it was running closed loop when they handed the motor over after fitting.

Right I need to check further but it appears even with the 02 sensors disconnected ensuring she is running on the default fuel map she is still running lean just over 10.2% (short term) bank 1 and 11.7% bank 2. does this imbalance suggest anything?

I think you are clutching at straws now and not getting anywhere.The car needs to be seen by someone who can read what is going on.

Easier said than done, local LR independent says he only really does tractors, nearest dealership is 40 miles away and not interested so bit short of options to be honest.

Some data from today, do all these readings look OK? Also find a misfire code showing No4.

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

bill told you i intrested in coming over and having a bash at fixing it please gfive me a call

Don't you read your emails Stu?

sorry mate up to my eye balls at the moment 4 engine jobs on the go very long hours am in all this weekend will mail you sunday when i have stopped