I've had my Disco 2 V8 for just over a year now and I've probably only had it on the road for 3-4 months out of that time. I'm at my wits end because now it won't run properly and no-one seems to know how to fix it.

When I bought it, there was a mixer LPG system on it. It was OK for a while, but after a few backfires (and resulting damage to air box - since replaced) I decided to have the front end reconverted. The chassis and body are in good shape and I thought at the time that it was worth spending the money, and my intention was to keep the car long term. I had a new Romano LPG system fitted.

A number of problems were discovered prior to reconverting. Petrol injectors needed to be cleaned and the ECU needed the adaptive settings to be cleared.

After I got it back, I discovered that it was using a small amount of petrol as well as LPG. This obviously wasn't right, and I sent it back to be fixed. At that point it seemed to be running quite well, smoothly, not missing, plenty power.

The investigations took many weeks. Entire LPG system was refitted, twice. It was discovered that the system was running fully rich due to sensor problems. TPS had a bad connection and was fixed. Lambda sensors were replaced. Eventually after a lot of head scratching the cause of the petrol usage was traced to a bad connection to the ECU, so the signal to switch off the fuel injectors was intermittent.

I got it back again but it was running very rough. Not too impressed about that, and don't know what changed to cause this. Suggestion was interference from the coil pack. I managed to drive it home and took it to my local mechanic. He has changed the coil pack, the distributor, and the leads and plugs but there is no improvement. The car is barely driveable, it will tick over but as soon as I accelerate it starts to miss and there is no power unless I really keep the revs up. At the moment it won't even switch over to LPG, but that's probably not the fault of the LPG system. The ECU shows multiple faults, which is suspicious, and my mechanic thinks is more likely to be an earthing problem. He did consider that the camshaft might be the problem, but compressions are OK and he didn't think this would cause such a sudden deterioration. Despite consulting with two other experienced mechanics, no-one seems to know what is wrong. I'm no mechanic so I'm just listening to what other people say.

So this is where we are today. Runs like a dog and no-one can find out what is wrong. Short of buying all sorts of parts (ECU, more sensors etc.) I don't know what to do next. I've already spent a small fortune on this car and it's still not right. What I am looking for is some good ideas of where to go next, or someone who can be fairly sure of fixing it if I was to bring it to them, without just clocking up more time on trial and error. It has MOT and could be driven - just.

I'm not interested in blaming anyone, but my LPG installer had run out of ideas, so not a lot of point in taking it back there. I just need a solution, and I don't know what alternative I have, since it's hardly going to attract many buyers in this condition. I might have to go out and buy a TD5 if I don't get this running soon, but I really can't afford to be buying an extra car just now.

Is there anyone who can help please?

Nightmare. I'm not that up on Thor, but others here are. I would get it running right on petrol first, but it is worth considering things that would effect both fuels, if it runs bad on both, so probably barking up the wrong tree here:
You say you replaced the air box but what about the air mass meter. Is it functioning correctly? Does unplugging it make running any different?

I thought this fred might be something else.

Im very dissapointed

vilguy said:

I thought this fred might be something else.

Im very dissapointed

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Me too, it was an interesting statement but the post is unrelated

No distributor on a D2 V8, are you sure that it has been changed? If so, you either haven't got a D2 or it's had a D1 engine fitted.

D2's on LPG are great, reliable and good to drive, IF everything is set up properly.

We've done 80000+ miles in ours, currently having the LPG tank straps replaced, but it has been faultless in that time as far as ignition/fuel matters go.

Our son's D2 V8 we converted ourselves to LPG and that's the same. He had a coil pack connector issue in France last year, but we had one of our spare packs shipped out and he changed it on the campsite, good as gold since.

It should run without a MAF on the backup fuel map, and there isn't a huge amount to go wrong, only things that have been fitted wrongly or incorrect parts.

You don't mention where you are, but if you're anywhere near us (NN10 0JT) pop over and we'll have a look at it and plug the Hawkeye in to see what's playing up.

Peter

Thor doesn't like LPG systems, only idiots use them.....

Thor1950 said:

Thor doesn't like LPG systems, only idiots use them.....

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LOL!

Peter

Thought you always ran on gas

listerdiesel said:

LOL!

Peter

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listerdiesel said:

No distributor on a D2 V8, are you sure that it has been changed? If so, you either haven't got a D2 or it's had a D1 engine fitted.

D2's on LPG are great, reliable and good to drive, IF everything is set up properly.

We've done 80000+ miles in ours, currently having the LPG tank straps replaced, but it has been faultless in that time as far as ignition/fuel matters go.

Our son's D2 V8 we converted ourselves to LPG and that's the same. He had a coil pack connector issue in France last year, but we had one of our spare packs shipped out and he changed it on the campsite, good as gold since.

It should run without a MAF on the backup fuel map, and there isn't a huge amount to go wrong, only things that have been fitted wrongly or incorrect parts.

You don't mention where you are, but if you're anywhere near us (NN10 0JT) pop over and we'll have a look at it and plug the Hawkeye in to see what's playing up.

Peter

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I could be wrong about the distributor. It's definitely a Thor. Has a bunch of bananas.

I've been to your workshop - you sold me a couple of pulleys about this time last year. I could get to you - when would be a good time?

ddriver said:

I could be wrong about the distributor. It's definitely a Thor. Has a bunch of bananas.

I've been to your workshop - you sold me a couple of pulleys about this time last year. I could get to you - when would be a good time?

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I remember, you wanted the idler pulley that goes in place of the air con.

We are working on Philip's Sankey build, so let me know which day, we can normally be around, as long as it isn't raining!

Peter

listerdiesel said:

I remember, you wanted the idler pulley that goes in place of the air con.

We are working on Philip's Sankey build, so let me know which day, we can normally be around, as long as it isn't raining!

Peter

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Going to be Tuesday at the earliest - the car is locked up in my mechanic's yard.

Should be OK, normal working day for us.

Peter

An update for interested parties:

On the Hawkeye, both Lambdas are inoperative.
There is a question mark about the venting arrangement of the LPG system into the inlet manifold.
The water feed arrangement to the vapouriser is inadequate but not causing the problems we are looking at.
We tried substituting a known good MAF which made no difference.

We advised the owner to get the Lambda sensors sorted out, and I should have asked him to check the fuses as well, I'll PM that to him in a minute. Fuse 2 feeds the Lambdas and MAF, plus the Purge Valve.

Once done, we can have another bash.

Peter

seems odd that curing the extra petrol leaking in was beginning of poor running,whether that is coincidence or not is another matter

It sounds 'mixture problem' but the exhaust doesn't smell over-rich.

Don't know if the excess fuel caused the Lambdas to die or not, Fuses are OK, OP has checked them.

The LPG installation is a bit of a mess, could do with tidying up in places.

Another point: LPG systems start on petrol, you do use a finite amount daily, more in the winter and as the heating for the vapouriser is through the throttle body feed, it would take a long time to heat up, staying on petrol longer.

Peter

Update:

The Lambdas were changed but didn't make much difference, the local Landy independent said to reset the ECU adaptions with Hawkeye, which we did and that made a big improvement.

Dave drove home and is going to drop me a message later to let us know how he got on.

Peter

Just read this thread and it sounds very similar to how my Disco is behaving, is your Disco still running fine after the ecu was reset?

Ah - quite a lot happened since then. The fault still persisted, and after trying lots of things I decided to seek out some experts. I hunted for someone who knew Rover V8s and LPG systems intimately. I found RPI Engineering in Norwich and they were brilliant. They quickly tracked it down to a wiring fault on the LPG system - both coil packs were connected together by the RPM signal connection, fixed that and it runs sweetly again.
The Lambda sensors not working turned out to be a different issue, and this was indeed an ECU fault. The sensors I have are still good. A new (used) ECU fixed this, and at the same time I decided to have the Mark Adams remap done. That makes a big difference to the way it drives, the torque is now available over the whole rev range, and the economy is much improved, I'm getting over 18MPG on LPG.

So all good now.