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Discussion Starter #1
As a quick recap I'd bought a blown HG range rover cheap 6 months ago, slowly I've done the headgaskets etc, then had to do the brake lines and sort the transmission cooler, running out of time and wanting to test the engine I booked it in for an MOT.

It failed on rear indicators not orange enough (new bulbs required)
It failed on brake pads all round (stupid of me not to check thickness)
It failed on headlight aim - one too high, one too low
It then failed on the emissions test - it failed so bad that they had to abandon the test :(

When it was first rebuilt - the exhaust had loads of steam coming out but that has now cleared, running on my drive it hadn't been smoking at all, and driving all the way there (approx 10 miles) it never smoked once that I noticed. It was also fine whilst there.

When it came to the emissions test I (maybe stupidly) thought it would be better to do it on LPG, so I put a bit of revs on and flicked it over to gas - kept the revs on for a few seconds then let go of the throttle, It cut out. I tried to restart on gas but it wouldn't start. So I flicked back to petrol and restarted (which took slightly longer than usual) then tried a final time to flick over to gas, I could keep it running with a little throttle but had to catch it to stop it cutting out when I let go, we gave up and switched back to petrol. It idled for about 30 seconds or so whilst he sorted the computer out, then I asked me to rev it to 2500rpm - when I did this we got clouds of smoke filling the garage - he said it was massively over fuelling. Dropping back to idle it continued to smoke a little.

He had to abandon the MOT at this point and sent me on my way, driving off it was smoking a little but after half a mile it cleared completley and didn't start smoking again. Not matter how hard I rev'd it.

Since getting back I've not even looked at just a bit worried about why it smoked so bad, I hadn't rev'd it that hard in Neautral as I had heard it was bad for the gearbox - is it OK at that level?

In general the RR drove well going there, gear changes were perfect (I had problems with it changing badly) but to me I felt it lacked power a little, it comfortably drove up to 70mph up and down hills but I just expected a little more, kickdown does give you a surge of power but again I'd expect more.

Any thoughts on the smoke?
 

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Discussion Starter #2
Just gone out to have a quick look.

Reving to 2000rpm doesn't seem to generate any smoke, reving to 2500rpm creates clouds of fuel smelling smoke.

No errors or warning on dash but appears to be over fuelling big style.

Could this be as simple as something like the lamda sensors or is something goosed?
 

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Discussion Starter #3
Just tried disconnecting the MAF sensor (plug on SAGEM unit) as I thought it'd run on default values if unplugged, it starts and dies straight away.

Plugged it back in and starts normally (took a little longer than normal - and kicked some fuel smelling smoke out) - is that right that it won't start with the MAF disconnected?

It has a K&N fitted (which I dislike) but on the end of the filter there is another electrical plug - what's that one for?
 

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It should run with the MAF disconnected, it won't run great, but it will run. If there is a problem with the MAF then you will notice an improvement in running with it disconnected. It could be a number of things, you might consider plugging an OBD scanner into it and seeing what it says with the live data and see if you can pull any codes. Just because there isn't a check engine light lit, doesn't mean there won't be any codes. I plugged into a Disco recently and it threw some misfire codes but the CEL was not lit (although that could be because he removed the light :think: ).
 

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I would go to another MOT station!

The emissions should be 1st job, whilst the engine is still warm and ideally don't even turn it off between arrival and test.

Rear indicators not orange enough? - the test is do they work, not how orange are they.
Similar goes for the brake pads. The test is a test on the day - they test the brakes and if they work there is no justification for a fail, even if there is 0.5mm left. OK they need changing but if they actually work its not a fail.
everywhere I have done an MOT if the headlight aim is out they do the really hard job of turning the adjuster on the spot.

Sounds a very iffy tester to me?
 

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Discussion Starter #6
The tester is OK,

The emissions made clouds of smoke there was no chance of it passing and the brake pads were less than 1.5mm to quote the UK MOT Handbook "f. a brake lining or pad insecure or less than 1.5mm thick at any point"

As for the indicators:

"d. that every direction indicator emits amber light, except vehicles first used before 1 September 1965 where both front indicators may be white and both rear indicators red"

They are looking rather white as the orange coating has worn off the bulbs, not an expensive repair!


Anyway neither of those points worry me - it's the engine smoke / over fueling which is worrying me.

There is definatley something wrong and I need to sort it,

I'm slightly concerned that it won't run without the MAF connected. I've been looking at some ODBII Readers on Ebay as I was thinking the same. Do you know if an ELM 327 USB type device will do the trick hooked up to my laptop - can get something like that for about £20. Most say suitable for most petrol vehicles from 2001, but am I right that the RR was using the OBDII standard back in 1998?

I have an EAS Unlock Cable but I'm fairly sure that can't be used in anyway, and I have a VAG-COM USB cable interface, but I think that only works with VAG-Group cars
 

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Hi

When I had a faulty MAF sensor unplugging it also let the engine die. I also couldn't get the engine to start with the MAF unplugged. Running with a faulty MAF sensor screws up the adaptive settings in the ECU. Even after installing a good working MAF sensor it took some time to get back to the normal fuel consumtion which was 50% higher with the faulty MAF. In my case a back fire of the engine caused by faulty rear mufler destroyed the MAF. It was the single most expensive item I ever had to buy for the car, but it cured the problem. At that point of time I didn't know anything about resetting adaptive values, but from what I read here doing a reset will instruct the ecu to start fresh with the factory settings.

I also have read on this forum that the K&N filter can cause an oil contamination that is affecting the operation of the MAF sensor. Try first cleaning it with electro cleaner as described on this forum many times.

The other connection you where asking about just after the filter is most likely the inlet air temperature sensor. It is possible to disconnect it and fit a resistyor with a fixed value in the connector. This will make the ECU believe that the temperature is low and inject more fuel to make up for the difference in density. It makes the engine more responsive but also causes the emissions to be higher.

Regards

Jos
 

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Discussion Starter #8
hmm that makes sense, sounds like I need to clean the MAF then get the adpative values reset.

When your MAF failed did you get clouds of smoke when revved?
 

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Hi

I did not try to rev the engine in neutral and look at the smoke. The car was driving ok but hesitant in picking up and the fuel consumption was calculated at 36 liters/100 km. It happened like 5 years ago and i can not recall seeing any unusual smoke while driving.

Regards

Jos
 

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Discussion Starter #10
Thanks for that - going to clean it tomorrow and see what difference it makes.

I just wish they had made it easier to reset adaptive values!
 

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I use a USB OBD II scanner on my rangie and it works great.
 

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Discussion Starter #12
Ordered a USB code scanner thing, should be here tomorrow.

Ordered Brake pads, just got to go and find some cleaner for the MAF then it's just fixing it! Hoping the oxygen sensors aren't stuffed as they won't be cheap to replace.

Got the pins to test on the ECM to work out what's happening from the Oxygen Sensors

One quetsion though - there are 4 pins to test for the Oxygen Sensors,

Bank A Upstream
Bank B Upstream
Bank A Downstream
Bank B Downstream

Do I need to test all 4 pins or is that due to some markets having 4 sensors? If so which two are the correct ones for me to test on my 2 sensor car?

Thanks
 

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Uk cars only have the 2 upstream (pre cat) sensors.

What lpg system do you have? Single point maybe? with or without lambda feedback?

If it is have you thought of having this tuned as it will not be relying on the MAF and if no lambda feedback, obviously won't be relying on this either. It also allows you to get an lpg emission test which allows much higher emission values.
At least you can then drive it once the MOT'd and sort out the adaptive values, although if single point these won't have any bearing on the lpg fuelling. Although poorly set lpg will have a negative effect on the petrol running by messing up the adaptive values,
 

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if it goes in running on LPG, then they should be doing a non-cat test, and the values are

3.5% c.o. content maximum
1200 ppm hydrocarbon content maximum

these are done at tick-over
 

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Discussion Starter #15
My idea was to take it in on Gas, I was unaware of the smoke at over 2000rpm as I was told the auto gearbox does not like to be revved without any load so I hadn't gone above 2k on the drive!

As I was driving there I switched to gas for a couple of miles just to make sure it was working, which it was. When I got there though I couldn't get it to idle on gas. Not sure if it was too low on gas or does gas go off like petrol after 18 months?

It has an Impco single point system
 

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I don't think lpg goes off - it's basically the same propane you can buy from calor for heating etc.
More likely if it has been left unused for 18 months the system has lost tune, a solenoid valve isn't opening fully or the rubber diaphragm in the vapouriser has perished/hardened.
Does it have O2 feedback?
 

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Discussion Starter #17
No idea on the o2 feedback - how would I know? It's an IMPCO single point system.

I presume it's pretty low on gas, it was running OK on gas and had an orange and green light on, now it only has an orange light on when I switch to gas.

Just can't really get it to a tuning place,

But before I get the LPG sorted I think I really need to sort the underlying issue which is making it run rich
 

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Discussion Starter #18
Managed to get it to pass the MOT! :dance:


Took it in with hot cats - ran it on high revs outside first until smoke cleared. Presented on LPG and it just scraped through.

Still doesn't solve my issue but atleast it's deemed roadworthy - and all the rest of the car has been checked over and is fine.

If it helps diagnose the readings were:

Fast Idle Test: (between 2500 and 3000rpm)

HC (ppm vol) (Max: 200) mine 19 - so that's one fine
CO (% v) (Max: 0.30) mine 0.30 - right on the limit
Lamda: (min 0.970 - max 1.03) mine 1.009 - OK I think

Idle Test:

Idle CO (% vol): (Max 00.50) Mine was 0.21


My problem is still there - but this makes things a little better as I can now road test. Just got to try and fix now.

Next thing will be a full set of proper compression test readings
 

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sotal said:
Managed to get it to pass the MOT! :dance:


Took it in with hot cats - ran it on high revs outside first until smoke cleared. Presented on LPG and it just scraped through.

Still doesn't solve my issue but atleast it's deemed roadworthy - and all the rest of the car has been checked over and is fine.

If it helps diagnose the readings were:

Fast Idle Test: (between 2500 and 3000rpm)

HC (ppm vol) (Max: 200) mine 19 - so that's one fine
CO (% v) (Max: 0.30) mine 0.30 - right on the limit
Lamda: (min 0.970 - max 1.03) mine 1.009 - OK I think

Idle Test:

Idle CO (% vol): (Max 00.50) Mine was 0.21


My problem is still there - but this makes things a little better as I can now road test. Just got to try and fix now.

Next thing will be a full set of proper compression test readings
Congrats on the pass - BUT You have a problem with your MOT tester - they have done the incorrect test :naughty: . The test they have done is for petrol. LPG is different - it is exactly the same as a non-cat test

There is no lambda test on lpg
HC limit is 1200ppm on lpg
CO limit on lpg is 3.5%


The HC's on lpg are different to those on petrol and a conversion factor has to be applied when using a gas analyser. If the tester has told the gas analyser it is testing a petrol car the conversion factor will not have been applied

So as an lpg car it hasn't scraped through - it has passed with flying colours :thumb:
 

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Discussion Starter #20
I've seen those figues you've mentioned a couple of times on the net,

but... I was round there with him when he went through the computer system, he put in the details etc then picked that it was presented on LPG the computer dealt with everything else. I don't know - I'm not complaining as it passed but it would be good to know for sure!

There is still a problem there though - you should have seen the cloud outside the MOT station as I desparatley tried to get the cats as hot as possible before it went in. The cloud filled the car park, luckily it wasn't near a road else I'd have been causing problems! After a minute or two at high revs it dissapeared and was good enough to pass.

I did notice a couple of times on the way home that when driving on gas after I had been cruising for a while then went to kickdown that it left a cloud of smoke in the distance it looked bluey coloured.

It appears to be burning oil on cylinder 3, Oil level drops quite quickly. The oil is then playing havoc with the lamda sensor, I'm not sure if it's suppressing a spark from the spark plug causing unburnt fuel to pass, but the short term fuel trims swing up and down on that bank. Coolant isn't dropping at all. Starts easily etc.
 
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