Chaps

Done a quick search but nothing's come up, so I'm wondering if anyone's had anything similar. My 4.4 V8's having a little episode and the LR dealer have been stumped by the ecu download (not surprising really).

I'm getting the reduced engine performance indicator on the dash and an occasional EML (although not always) and to be honest the performance isn't reduced, it's just not right. The engine surges up / down about 100rpm when on a constant throttle between 1200 & 1600 rpm so it makes driving it quite uncomfortable, it's like driving a ship ! They downloaded the fault codes last week and came up with MAF sensor issues, lambda issues, running lean & running rich on a couple of cylinders. They've blamed it on the LPG system & the K&N airfilter so consequently wont touch it, which is fair enough and something I've always accepted.

Trouble is, all these issues are when it's running on petrol, I'm rarely on LPG at the moment and haven't been for a while, so although I know the lean /rich fault is due to the LPG, in my view the MAF & lambda aren't, so I'm wondering if anyone here has had MAF or lambda sensor issues on a petrol V8 RRS ? I'm going to ask the same on the D3 forum to see of anyone there's had it as well, but all help / ideas greatly appreciated. Does anyone know if the MAF sensor is self cleaning or if the oiled filter screws them up ??

Thanks for reading what is a bit of a long post, but although I've got some ideas I'm a bit stumped with this one.

Cheers

Mike. Ex-G4 Challenge RRS HSE, BV55 YZE. Subtle shade of orange ! Now registered YZE481 G4RRS in Melbourne.

Ive known this happen on subaru's it causes premature engine failures on subaru's because engines are so finely tuned that when you fit certain filters that arn't ideal for that vehicle dispite what the supplying manufacturer say some people find out the hard way so changing the maf and lambda sensors at regular intervals was recommened otherwise it causes the problem which you are having and will end up melting your pistons if its running too weak just like many subaru owners have experianced or try getting it remapped with your modifications you've had done so its better suited to the air & fuel mix its now getting.
Ady

Yep, had the same with my old Subaru, cleaned the maf sensor and put a standard filter back in there. MAF's & lambda sensors seem to be consumable items on some cars.

Have just cleaned the maf sensor, to be honest the wires were a filthy grey dusty colour and now they're shiny, so that may well help. Ex-G4 Challenge RRS HSE, BV55 YZE. Subtle shade of orange ! Now registered YZE481 G4RRS in Melbourne.

After lots of diagnostics from a friendly independant, 3 idle breather valves and a few pointers from the D3 forum, last week I ended up replacing the throttle body (under warranty, thank you Land Rover) and all seems to be hunky dory now.

Annoying as hell this has been, it was clearly an air leak that was allowing over pressurisation of the breather system and the wavering revs, causing it to run rich / lean then trigger the EML. Taking the inlet pipe off showed a throttle butterfly caked in oil and not closing properly, looks like the buildup of oil over time from the part idle breather pipe had gunged it up and put stress on the actuating motor, causing it not to close properly. Cleaned it all up and stopped the reduced engine performance warnings but it still wasn't right and kept blowing the breather valve. Anyway, after an email to LR technical by Stu Armson of Armson AE (the indy I've been using to trace the faults) with all the details and the suggestions from Disco3.co.uk from a north american D3 owner about the exact same fault, LR tech agreed and that then sent me to Stratstones in Newport with all the information. Demoed it, talked it through and they agreed with me and managed to get the TB under warranty.

I now have a smooth running engine and strangely, much better gearchanges, the box is actually working properly, no more *clunks* as I pull away.

So, a bit long winded but I've got there in the end, thanks to the power of the forums and a dedicated independant who was willing to go above and beyond to solve the problem.

Oh and my mpg's rocketed, last week it was down to 14mpg, already it's back up to nearly 20  Ex-G4 Challenge RRS HSE, BV55 YZE. Subtle shade of orange ! Now registered YZE481 G4RRS in Melbourne.