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MAF is **** near spot on, Nanocom documentation says at idle it should be showing mid-20s (and you can't get much more mid than 25), rising progressively to 200 at 5,500 rpm. Everything else looks correct too.

No vacuum when you take the filler cap off might be relevant though.

No need to disconnect the LPG system if you haven't been running on gas, there won't be any gas in the reducer to leak into the manifold anyway.
 

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1996 Range Rover P38A
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Discussion Starter #22
I think the alternator voltage thing is a red herring... Have you cleaned/ reset the IACV? As Richard says, IAT probably doesn't have much impact here, but you can search for one of my posts here which details a shunt you can wire in if you want. Maybe post up some nanocom diagnostics so we have the full picture? My over-fuelling seemed to get sorted when I had the injectors cleaned, but you've already covered that. Have you checked the spark on all cylinders? May also be something to do with EGR (beyond my pay grade)
The main reason for chasing the voltage was because of the sticky clearly stating MUST be over 14.2V, and mine isn't. In the past I'd also has gearbox fault errors and that was cured by testing and changing the battery cables, plus adding a short strap direct from alternator to battery, no issues since.

The injectors were tested by a company in Wiltshire, I'll try and find the report, but basically there was bugger all wrong with them, not even dirty let alone leaking.
 

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Discussion Starter #23
MAF is **** near spot on, Nanocom documentation says at idle it should be showing mid-20s (and you can't get much more mid than 25), rising progressively to 200 at 5,500 rpm. Everything else looks correct too.

No vacuum when you take the filler cap off might be relevant though.

No need to disconnect the LPG system if you haven't been running on gas, there won't be any gas in the reducer to leak into the manifold anyway.
Ok, we'll start with the purge valve then. I'll disconnect it and see what results it yields, if any.
 

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Discussion Starter #25
You didn't damage the very thin wires in MAF when cleaning it with brush ??
There not really wires, I think the one is a thermister, not sure what the other component is.
Attached is an image of the business end for those that are interested.
286892
 

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Discussion Starter #26
Richard, the reverse side of the LPG ECU didn't reveal much. Attached is an image if it means anything to you.
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The electrical sticky is wrong if you are dealing with an older car. The alternator set point on an early car was under 14V, usually around 13.7V, but later batteries with a higher Calcium content can withstand a higher charge rate so the later alternators have a set point at 14.4V. So on a later car you would be looking for 14.2V but around 13.6V on an early one.

If the battery voltage to the gearbox ECU drops to below about 10.5V, usually during cranking or if the battery is past it's best (or just flat), that will bring up the Gearbox Fault.

Purge valve does seem like it might be the only remaining common point that will cause over fuelling, so it's worth plugging the hole and seeing if that makes a difference.

If the LPG system was working fine, then the ECU model is pretty irrelevant. Even if it is a re-badged AEB, it will have Tartarini firmware so only the correct Tartarini software will connect anyway.
 

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Discussion Starter #28
The electrical sticky is wrong if you are dealing with an older car. The alternator set point on an early car was under 14V, usually around 13.7V, but later batteries with a higher Calcium content can withstand a higher charge rate so the later alternators have a set point at 14.4V. So on a later car you would be looking for 14.2V but around 13.6V on an early one.

If the battery voltage to the gearbox ECU drops to below about 10.5V, usually during cranking or if the battery is past it's best (or just flat), that will bring up the Gearbox Fault.

Purge valve does seem like it might be the only remaining common point that will cause over fuelling, so it's worth plugging the hole and seeing if that makes a difference.

If the LPG system was working fine, then the ECU model is pretty irrelevant. Even if it is a re-badged AEB, it will have Tartarini firmware so only the correct Tartarini software will connect anyway.
Would it be within your power to have the sticky amended? I'd already searched the forum for the part number for a higher rated voltage regulator and I would have bought one until you mentioned about the older models.

This forum is already a world class resource, small amendments here and there can only make it even better.
 

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Discussion Starter #29
A bit of 5mm 'O' ring cord is a snug fit within the bore for the sake of testing. If we get a result I'll tap it 6mm and plug it off.

I'm quietly optimistic about this, fingers crossed.
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This forum is already a world class resource, small amendments here and there can only make it even better.
Well, it used to be, until it was castrated and all the useful stuff removed......

However, there are plans for the common problems section to be updated and published on an alternative site as the owners of this one don't seem to understand how useful it was and, despite saying they will be put back for the last year, they still haven't done anything about it.
 

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Thanks for the nano screen shots. As static data that all looks pretty normal for idle.

IACV % (really Steps not %, BBS has it wrong) shd be more like 22.5 +/-7.5 - might be worth cleaning/ adjusting. The retaining bolts are v weak (m3 , or something) if the IACV bolts don't budge, then i suggest it's not worth forcing (unless you are replacing, and have some replacement bolts). The adjustment can be done form above (you may have to remove a blanking plug) - and the adjustment needs an odd-sized allen key, if IIRC 5.5mm, or it cd have been 4.5mm. A torx key will do, at a push.

Are your o2 sensors looking ok?
 

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Would it be within your power to have the sticky amended? I'd already searched the forum for the part number for a higher rated voltage regulator and I would have bought one until you mentioned about the older models.

This forum is already a world class resource, small amendments here and there can only make it even better.
It's still worth buying the higher rated VR, for the sake of your battery - I was just meaning that the regulated voltage is in spec, as Richard says, and so shdn't be causing fuelling issues.
 

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Discussion Starter #33
Thanks for the nano screen shots. As static data that all looks pretty normal for idle.

IACV % (really Steps not %, BBS has it wrong) shd be more like 22.5 +/-7.5 - might be worth cleaning/ adjusting. The retaining bolts are v weak (m3 , or something) if the IACV bolts don't budge, then i suggest it's not worth forcing (unless you are replacing, and have some replacement bolts). The adjustment can be done form above (you may have to remove a blanking plug) - and the adjustment needs an odd-sized allen key, if IIRC 5.5mm, or it cd have been 4.5mm. A torx key will do, at a push.

Are your o2 sensors looking ok?
The IACV value is high in that screenshot because the AC had just engaged, and obviously the IACV had just spun out a bit to compensate for the load. Usually its bang on 22.
The allan key you speak of is imperial, 3/16". I realise we went metric 45 odd years ago, by why spoil the habit of a lifetime!! I've had that adjusting screw out several times because its gets gunked up from the rocker box vent pipe, which is right next to it. Clever eh? Err....no.

The o2 sensors appear to be working ok, there are no error codes and they cycle correctly. I loath to change them for the sake of it because they are expensive. I like to test things, prove that they are serviceable. If I can prove they are not servicable then I'll change them.

The last time I got stuck into this problem, everyone was suggesting the injectors were leaking and I should replace them. I had them tested for the fraction of the price of a new set, and as it happened there was nothing wrong with them.
 

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Discussion Starter #34
It's still worth buying the higher rated VR, for the sake of your battery - I was just meaning that the regulated voltage is in spec, as Richard says, and so shdn't be causing fuelling issues.
In my own experience, low voltage causes the weirdest of problems. My reasoning was that if sensors were not getting their full voltage there not going to report accurately, I'm also inclined to repair anything that's at fault.
The electrical system, in particular, the charging circuit appears to be functioning as it should, so normally I wouldn't fix anything that isnt broken.

However.

I do a lot of short journeys, so i do agree with you, it would be a useful upgrade, but I'll be sure we've fixed the current problem first.
 

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Although the cam sensor and MAF have a direct supply at battery voltage (the same Brown/Orange wire as the petrol injevctors) them and all the other sensors (temp, TPS, knock and crank) all run off a 5V regulated supply from the engine ECU (Red/Black wire), so battery voltage is pretty much irrelevant.
 

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Discussion Starter #36
Although the cam sensor and MAF have a direct supply at battery voltage (the same Brown/Orange wire as the petrol injevctors) them and all the other sensors (temp, TPS, knock and crank) all run off a 5V regulated supply from the engine ECU (Red/Black wire), so battery voltage is pretty much irrelevant.
That's certainly worth knowing, thank you very much.
 

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Discussion Starter #37
The report from the injector test.
The graph looks quite dramatic, until you look at the numbers, then you realise there wasn't much in it, and no leakage.
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arudge, same guys did my injectors, and although the report didn't come back with much either (one was leaky) - in practice they resolved over-fuelling ( petrol smell at idle), and seemingly a hot start problem associated with heat on the fuel rail - neither of which have recurred since refitting. I know the bar chart is the sexy part, but also take a look at the spray patterns. I wonder if it's worth looking at your injector no 3? Mine all came back 222-225
 

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Discussion Starter #39
arudge, same guys did my injectors, and although the report didn't come back with much either (one was leaky) - in practice they resolved over-fuelling ( petrol smell at idle), and seemingly a hot start problem associated with heat on the fuel rail - neither of which have recurred since refitting. I know the bar chart is the sexy part, but also take a look at the spray patterns. I wonder if it's worth looking at your injector no 3? Mine all came back 222-225
I'm not sure what your looking at there mate, the injector patterns all came back good, number 3 was tested as good before cleaning anyway. On the chart, number 3 was down on flow at 216 before cleaning but came back 225 after cleaning, along with all the others.
 

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ah yes - you're right, ignore me.

Have you cleaned your O2 sensors? But be prepared for one of them to be frozen into the pipe and so lose the thread ... When I change my exhaust I replaced mine with Lemark ones (ie not so expensive)nine months ago. For a few weeks I had a rough idle (my intepretation was that it took a while for the sensors to run in, although apparently they shouldn't need to). Since then all has been well
 
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