TD5 Engine Fault Light

Hi All, had a gas conversion done & now have intermittent fault with engine fault light. had lamda sensors changed but still have problem.
fault appears when driving on petrol or lpg but has no effect on performance, garage says it's to do with 'adaptive mixture'?? but offered no solutions. has anyone got any ideas how to resolve this??
Cheers kenp

that'll be because a TD5 is a diesel engine and gas conversions are for petrol engines...

I dunno.... drawing in me into your thread under false pretences....

TD5 was referring to the model wish it was diesel wouldn't have these problems!! it's a 4.0L V8 petrol / lpg

Sounds like you have chosen to use a garage or LPG installer that does not know how to fit LPG or tune it properly.The check engine light has come on because the LPG is not fuelling the engine properly - the petrol ECU is still running whilst on Lpg,and monitoring fuel mixture.By the way it will still be controlling the sparks,but if the Lpg is poorly set up the feedback from the oxygen sensors will not be what the petrol ecu wants to see so it puts the light on.Trouble is most Lpg installers seem to think that the "autocal" in the LPG ECU software is all they need to do,thing is the Bosch Motronic petrol ECU is very clever,so you need to set the gas up on the road,altering the fuel map whilst monitoring BOTH upstream oxygen sensors with an Oscilliscope.Not many places have the kit or know how to use it.

garage have carried out all set up procedures with pc on the road (adjusting mapping whilst on the move, with myself present - in the vehicle) & seem v.knowledgable!! problem appears also if i run on petrol only so i think it's possibly something to do with the wiring, occurring during the conversion. I heard you can simulate sensor faults by baring the sensor wire & holding it between finger & thumb, thus altering the resistance enough to make the ecu think there is a fault!! Not sure but could be something along these lines??
Thanks for the feedback anyway, any other ideas???
Cheers Kenp

Now you tell us ! So if it ran properly on petrol before the conversion and has faulted since on both fuels it has,(obviously) to be caused by the conversion work.
The Thor,(banana manifold) engine is difficult to fit LPG to because of the shape of the manifold and the difficulty of getting the gas injector pipes and wiring down through the gaps without dislodging anything or trapping it under the manifold face.
Fraid its down to the installers to sort it out,I'm suprised they even let you ride in it in that state.Do you know the exact fault codes that were generated?

kenp said:

TD5 was referring to the model wish it was diesel wouldn't have these problems!! it's a 4.0L V8 petrol / lpg

Click to expand...

HELP!!!!

Someone please explain to me what "TD5" has got to do with a 4 litre V-8 petrol engined LandRover Discovery.

I really want to know.

CharlesY

UPDATE: installer now tells me he thinks there is a problem with the ecu itself!! states there is a company who could re-program / unblock the ecu itself!!
anyone heard of this or know wot company carries out this re-programming??
cheers kenp

1, Bosch Motronic ECU's are very reliable.
2,My experience of companies that test/repair them struggle with more complex modern ones and cannot fully test them.
3,If there is an ECU fault it would be much more sensible,(and probably cheaper) to borrow another one off a similar car and do a "security relearn" with Testbook and run that.(The borrowed ECU would need a relearn when replaced back on its original car.
4,Its much more likely to be a cabling fault,the wires are very tightly packed into the loom near the ECU and the LPG installer will need to get into that loom to tap into several wires.If any of the pins were not pushed fully home into the multiplugs its very possible that they have backed out or not making a good enough connection.

Right,

I have a disco 2, (TD5 model as you called it) It is also a 4.0 V8 running on a BRC sequential system.

My first question is this:

Have you had a sequential system fitted? i.e. are there 8 gas injectors under the bonnet individually feeding into the inlet manifold?

if there are not then you have a single point system installed which, I am sad to say, will not work efficently on the Thor management system.

regards

The LPG installer will only tap into the injector loom and this is simply plug and play on the sequential systems.

thnx for that. wil suggest it to the installer i have to visit again on the 19th.
will keep you posted on the outcome!!
cheers
kenp

thnx 4 the feedback will check it out

initially there were faults indicating lambda sensors pre-cat, i had these replaced. then faults indicated post cat sensors i also had these replaced. fault now indicates adaptive mixture fault!! all new 2 me as a newcomer to the land rover club!!

CharlesY said:

HELP!!!!

Someone please explain to me what "TD5" has got to do with a 4 litre V-8 petrol engined LandRover Discovery.

I really want to know.

CharlesY

Click to expand...

sorry was referring to shape a dealer told me to refer to it as td5 wen i was after some spares!! it's a disco 2 v8 4.0l.

M Unit said:

The LPG installer will only tap into the injector loom and this is simply plug and play on the sequential systems.

Click to expand...

Oh,right - maybe you want to have another look,if you have ever tried to fit/refit sequential LPG to a Thor engine you will know what I was dribbling on about.