Disco 4.4 V8 System Too Lean EML

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philsteward
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Disco 4.4 V8 System Too Lean EML

#1 Post by philsteward » Tue Oct 13, 2020 9:14 am

Hi all, hope it is okay to post this.

I have a 2005 Disco 3 with a 4.4v8 and a BRC LPG kit. It runs okay, but has started coming up with system too lean on both banks. P0171 & P0174 codes.

It does this on both petrol and LPG. There was a bit of rough idle occasionally when it first started but I changed the PCV and this went away, but the codes keep coming back.

I have done obvious checks for vacuum leaks, and even checked the MAP which was clean and the engine ran terrible when removed.

Does anyone have any suggestions?
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

Gilbertd
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Re: Disco 4.4 V8 System Too Lean EML

#2 Post by Gilbertd » Tue Oct 13, 2020 10:32 am

As the LPG system slaves off the petrol system, if it's lean on petrol it will be lean on LPG. So ignore the LPG system and concentrate on the petrol system for the fault.
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Re: Disco 4.4 V8 System Too Lean EML

#3 Post by philsteward » Tue Oct 13, 2020 10:56 am

Hi, yes thanks exactly what I am trying. Realise this is a LPG forum, but my local garages seem to just point at the LPG system which I know it is not. Hence after any tips here to find the problem.
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

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Re: Disco 4.4 V8 System Too Lean EML

#4 Post by Gilbertd » Tue Oct 13, 2020 11:28 am

That's the usual problem, they don't understand it, it wasn't put there by the manufacturer so it must be that causing the problem. Obviously if any of the additional vacuum pipes added for the LPG system are leaking then that will cause it, but if you've checked them and not found a problem, then you are looking at something else.
96 Saab 900XS, AEB Leo, sold
93 Range Rover 4.2LSE, Lovato LovEco, sold
97 Range Rover 4.0SE, multipoint, sold
98 Ex-Police Range Rover 4.0, AEB Leo, daily motor
96 Range Rover 4.6HSE Ascot, AEB Leo, my spare


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philsteward
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Re: Disco 4.4 V8 System Too Lean EML

#5 Post by philsteward » Tue Oct 13, 2020 11:56 am

Does anyone know a knowledgeable garage or individual who knows the 4.4 V8 engine in the Yorkshire area?
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

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Re: Disco 4.4 V8 System Too Lean EML

#6 Post by Gilbertd » Tue Oct 13, 2020 1:38 pm

There's Simon, LPGC, who's just north of Doncaster (have a look at any of his posts on here for his contact details), the only other person I can think of with plenty of experience of Land Rovers on LPG is Mick at Fox Vehicles but he's in Cambridgeshire so a bit of a run for you.
96 Saab 900XS, AEB Leo, sold
93 Range Rover 4.2LSE, Lovato LovEco, sold
97 Range Rover 4.0SE, multipoint, sold
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96 Range Rover 4.6HSE Ascot, AEB Leo, my spare


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Re: Disco 4.4 V8 System Too Lean EML

#7 Post by Brian_H » Tue Oct 13, 2020 9:21 pm

The earlier ones with the Bosch injection system are very picky about the MAF - If its been swapped is it a proper branded one you have fitted (someone more knowledgeable with them would know what the oem brand was, at a guess possibly Bosch?) or an aftermarket one? If its aftermarket that may be the issue in itself, even if new. Might help if you have some access to live data to see what the sensor is detecting and compare to what it should be showing up, Only problem may be getting a known good one to compare to unless you can find some info on what you should be seeing there (might be a job for a suitable forum specific to the vehicle there as your more likely to get an answer, but if you can get that it may be worth a post here with what info you can get).

Simon would be a good bet to contact though as if it is an issue with the LPG system he will identify what it is and sort it, or if its something else should be able to give you a good idea where to look at.

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Re: Disco 4.4 V8 System Too Lean EML

#8 Post by Fox vehicles » Tue Oct 13, 2020 9:33 pm

Hi, is the eml constantly on or does it take a while after reset? Also have you had a smoke machine connected to the engine? I can be difficult to find some air leaks but a smoker will show them up. Would be good to rule out air leaks before you go to much further I would say. Also do you have access to a OBD code reader to get a look at fuel trims and oxygen sensor readings also freeze frame data will help.
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Re: Disco 4.4 V8 System Too Lean EML

#9 Post by philsteward » Tue Oct 13, 2020 9:41 pm

Thanks a lot for your comments.

I have changed the MAF sensor, this was sometime back with a genuine one. This was in an attempt to improve minor hunting at about 1200 revs, which it didn't do! I have tried putting the old MAF sensor back in and it still brings up the fault code after a few starts/miles of driving. EML doesn't come straight back on.

I have not changed the MAP sensor. This is what I mentioned in my first post. I have removed it and cleaned it as the Disco3 forum said these can display lean codes when faulty.

I have access to live data, I have an IIDTool which is specific for the car. What would you want to see?

The only outstanding point is that the Disco3 forum seems to suggest the Manifold Absolute Pressure reading should be around 100kpa, mine is reading around 25kpa on idle and 40kpa when revved.

I have no way of swapping the MAP sensor without buying a new genuine one which I'm loathed to do without testing it.

Happy to get live data readings for fuel trims and oxygen etc. They look no different though to what they have been for the last 5 years as I checked them. Can't remember the figures off the top of my head though!

I haven't been on a smoke machine, that's a good idea. The car has no cats though incase that makes any difference anywhere...
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

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Re: Disco 4.4 V8 System Too Lean EML

#10 Post by Fox vehicles » Tue Oct 13, 2020 10:02 pm

If the cats have been removed I would expect rear probe faults, but shouldn't make it run lean I don't think. If you have a good look at the freeze frame data once the eml comes on again it should tell you the long & short fuel trims for both banks also the oxygen sensor readings and everything else that's going on at that point, which can quite often point you in the right direction. If you can get access to a smoker, try that first, best to rule out the simple things first. Is there a valve saver system fitted along with the LPG conversion?
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Re: Disco 4.4 V8 System Too Lean EML

#11 Post by philsteward » Tue Oct 13, 2020 10:46 pm

Post cat lambdas are on extenders and haven't shown faults since it was done 4 years ago.

I'll do that tomorrow with the freeze frame data, thanks.

There is no valve saver system. I never got round to fitting it after I rebuilt the engine following valve seat recession when I bought it. So I am aware of the issues, but fairly confident it isn't that as both banks have the fault and there is no rough idle or any of the other common symptoms plus only done about 30k miles since the heads were redone. Still, realise it is a possibility 😬
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

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Re: Disco 4.4 V8 System Too Lean EML

#12 Post by Fox vehicles » Fri Oct 16, 2020 1:48 pm

Fingers crossed then mate :) I would be supprised if there was vsr in 30k Let us know how you get on :D
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Re: Disco 4.4 V8 System Too Lean EML

#13 Post by philsteward » Fri Oct 16, 2020 10:40 pm

So, sent the car for its MOT as that is due in a month, and it failed for high CO2 levels, or unburnt fuel. Got a smoke test done and there is smoke coming out of the intake in various places. Figures crossed this is the issue and will keep you all updated!
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

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Re: Disco 4.4 V8 System Too Lean EML

#14 Post by Fox vehicles » Tue Oct 20, 2020 1:06 pm

Sounds like a good place to start :) I'm guessing they tested the emmissions on LPG and not Petrol :wink:
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Re: Disco 4.4 V8 System Too Lean EML

#15 Post by LPGC » Tue Oct 20, 2020 8:02 pm

Interesting that the smoke test revealed manifold leaks (which would be vacuum leaks when the engine is running). Where exactly on the manifold were the leaks?
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Re: Disco 4.4 V8 System Too Lean EML

#16 Post by philsteward » Tue Oct 20, 2020 8:10 pm

I haven't seen it myself, just getting the last bits together to do my own DIY smoke test.

The garage told me it was coming out of the baffles just after the MAF. Also coming out from near the EGR valve vacuum connector and out of the driver's side of the engine. Last one must be either the plastic intake has cracked or the seal to the head has failed.

If anyone has any suggestions let me know!
2005 Land Rover Discovery 4.4 v8 with BRC
1971 Land Rover Series 3 with LPG

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