Hello, could someone please advise me what i could be up against. I have only had my L322 2003 4.4 for a month and it doesn,t seem to be running as well as it should, it seems to miss when there is any load or when i accelerate, sometimes it seems worse than others, it doesn,t matter whether it is hot or cold. I changed plugs and took it for a run and it seemed better but next time i went out same problem, cruising along at 70 klm it feels smooth but touch the go peddle and the engine management light comes on and it feels all jerky. I am waiting for a fault reader ( just a cheepy) then i may be able to find out more without going to the stealer,
Any advise in the meantime would be appreciated.

Sorry to hear and sorry to say, it could be a whole number of issues.

Do you hear any VANOS rattling going on apart maybe from start up ?? When those systems get older they start developing some issues that could result in problems like you are describing.

Second potential is fuel system. Filters clean ?? Try to run injector cleaner for a bit, the BM44 or something recommended on here, if you can get it Down Under. On my SC I had the entire fuel system cleaned and updated the software (I have a Faultmate) and I suggest that you see if you can get the software updated as well, just to be sure that it isn't an issue with that. Also the entire inlet manifold was cleaned. After that, no more EML or other issues but that was a 4.2 SC that had been sitting still in the Nigerian sun for 2 years.

Next potential issue is electrics, ignition coils, wiring etc. Maybe after 12 years in the heat the insulation is getting a bit worse for the wear, plugs getting tired etc.

A fairly simple one is the MAF sensor, you will find it behind the air filter on its way to the engine somewhere. I don't know the early models location of the MAF, only on the 4.2. Take it out, clean it with good quality medicinal grade alcohol or brake cleaner, let it dry and put it back in. I used a cotton bud to gently wipe it clean.

It sound like fuel/ignition related. Even the accelerator could be the problem, as it is a potentiometer. Some WD-40 or contact cleaner on it could make a difference as well.

Hope this is of help and keep us posted please on how you go  MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

When I bought my 4.2 S.C. about 6 months back privately I had a bit of a shock with the yellow engine management light coming on the following morning after taking SWMBO down to the shops for a run... I thought WTF... the drive home the previous afternoon was one of the best drives I have had in years from Hereford through Brecon down the valley to Swansea with no issues whatsoever. After taking some advice from a mechanic mate of mine I filled the tank with the best unleaded money can buy, added a bottle of injector cleaner and gave it an italian tune up down the M4 for a junction or two and returned home... The following day the light went out on my way to work and hasnt come on since, I always use the best petrol whichever staion I pull into and repeated the proedure above a few tanks later with no issues since thank ...

With non-critical faults, the car will remove the fault warning light after a certain number of successful "drive cycles" (start stops). I think it still saves the fault info so you can get it with a code reader.