V12 Daimler Addict

[MackV12]

Several months back I bought a '95 V12 Daimler with an LPG conversion. The car was in a real state and it has taken 3 months of mechanical and body work to get it driveable.

The LPG installation is basic, a couple of mixers inserted in the air intakes, a Leonardo ECU, with a couple of Pitagora emulators - see photo's:

https://www.flickr.com/photos/95537991@N05/

The airfilters have been junked for some new ones. Not sure why the airfilters had an ally restrictor in them, although I suspect you are going to tell me I have been a @!## removing them. The mixers were joined to the air intake with 3 bolts and a lot of silicone sealant. the air box and tubing have been butchered. There is a spare wheel tank in the boot, but the filler needs an adapter to fill and is at a weird angle on the inner part of the boot wing.

From my inspection of the LPG installation, I am not sure if it is safe. As an IT guy there must be a lead/software I can buy to tell me what the system is doing?

The light does come on the gas switch and it does flash orange, but it does not seem to do anything.

I am based in the North West so any recommendations for an LPG installer to check the system out would also be appreciated.

[LPGC]

Just the one Leonardo ECU?

Hard to say whether it's safe or not given the pics I've seen...

Not sure why the airfilters had an ally restrictor in them, although I suspect you are going to tell me I have been a @!## removing them

A restriction anywhere in the airflow before before the mixer may richen the mixture a little. The aftermarket gauze airfilters generally flow better than OEM panel filters - if the combination of venturi size in the mixer and sensitivity of the reducer won't allow a rich enough mixture an installer may have fitted the restrictors as a means to create a richer mixture. The other reason, if the restrictors were forward facing, could be to prevent any ram air effect.

TinleyTech will sell you a cable for the Leo.

Simon
Lpgc

[rossko]

Filler won't do; the boot needs to be open for filling, so any spill will go inside the car. There aren't many nice options for the XJ body, a hole in the wing or a towbar mount perhaps.

The discarded restrictors probably mean it was running lean without them, because the mixers are too big (but quite possibly were the only ones available to fit the throttle bodies)

Yes, Leo software and leads are available.

[Gilbertd]

The flashing yellow LED on the Leo means that it is waiting to change over. To change over it needs to see pulses from the ignition to tell it the engine is running and it needs to have reached whatever revs the changeover has been set to. Usual setting is something like deceleration at 1,300 rpm, so it will change as the revs drop from over that. Manual and software for the Leo used to be a download from the AEB website but it seems they have now updated their site and removed it, I've got both if you need them.

The restrictors will have been fitted as the free flow air filters won't have put enough restriction in the airflow so the gas wouldn't be drawn in. If you have changed for the original air boxes then you shouldn't need them.

[classicswede]

The restriction on the air filters were almost certainly fitted due to not enough suction from the mixer on the vapouriser. This could be due to a mismatch of mixer/vapouriser or due to the lack of restriction from the air filters. The original filter might have been changed due to a backfire.

The Leo is going to want re calibrating for all the changes that have been made

[MackV12]

Thanks all for info - gratefully received.

Had a laugh about retaining the original airfilters, as the V12 engine takes a huge amount of space. My gripe is the way the LPG installer butcher the original airfilters/inlet tubing. Certainly the original sized airfilters would not allow LPG fitment.

The AEB cable/software/manual looks the way to go.

Found a link for the AEB v2.7 software on Tinley (http://www.autotanks.com/download.html) - not sure it is right one.

The offer of a copy of the manual would be appreciated.

I will give Tinley a bell about the cable.

[Gilbertd]

I run version 3.1.0 of the software but I don't think it makes much difference, it's pretty basic. I once had an earlier Double Six, a 1980 something so I know what you mean about it being a bit crowded under the bonnet. If I remember right that had a pair of huge metal oil bath air filters on it. The ideal place for the mixers is directly onto the throttle bodies if you can and then shorten the intake trunking to the air filters.

[MackV12]

A lead for the Leo is on my purchase list.

Had a read through the manual. Curious that it only covers 2-8 cylinder engines, begs the questions how is it running a 12 cylinder engine?

Maybe there is another Leo in the engine bay I have not found yet....

[rossko]

It doesn't really have any clue or care how many cylinders there are, it's only meaningful for getting a RPM display. The RPM is actually used for minor control tasks, but as you can alter the thresholds for those tasks to suit a misreading RPM it doesn't matter much.

The control element is a stepper motor valve in the gas feed. Most likely you have two? wired in parallel. It's not ideal due to risk of overloading Leo's output, and relies on the hope that the steppers stay in synch each drive, but it does generally work.

[Gilbertd]

If you were to tell the Leo you have a 6 cylinder engine, it will think it is revving twice as high as it really is but by changing the coil setting to Dual coil, you can probably get it to read right.

Most likely you have two? wired in parallel.

Or one in the hose before it splits to feed the two mixers. Again not ideal as the stepper valve, or actuator as AEB refer to it, needs to be as close to the mixer as possible.

[classicswede]

Looking back the photos the hose goes from the reducer to the stepper to the mixer with no Y. Does that mean that you have 2 reducers / vaporisers with one feeding each mixer?

I'm sure when I did one of these many years ago I put internal mixers in and moved the idle control pipe so as to retain the original air box.

BTW the shallow type mixer you have in the photos does not produce as much suction as the normal deeper ones do.

[MackV12]

I can confirm there are 2 reducers / vaporisers feeding the 2 mixers. The single Leo 175 seems to be driving them both.

The current mixers have 3 bolts that dig into the plastic trucking and have deformed the trunking. You can see in the photo's the deformed and largely butchered trunking and the huge amount of silicone sealant that was used to seal between the mixers to the trunking.

I would like to replace the trunking and probably the mixers.

Any recommendations with what and on where I can get suitable mixers & trunking?

[classicswede]

1 Leo driving two stepper motors is not a good idea. The steppers are likely to go out of sync and cause problems with mixture imbalance.

For the trunking you are looking at either a specialist breakers or a new one from the dealer.

[MackV12]

Not sure how long the LPG kit has been on the car but it looks like quite a while as the pipe work and electrical wiring is looking a bit tired.

My aim is to get LPG kit working and take it from there. I now have the software, the leads and a manual, all I need now is the garage to finish with the air con, so I can have the car back.....

As for the air trunking I will replace it with aftermarket parts that match the mixers diameter. Right now there is a huge amount of silicone filling the gap. Did I mention that one of the holes in the air trunking is filled with a wine cork?

Thanks to all for your advice, really appreciate it.

[MackV12]

Update time.

Ok so I have the Leo software, plugged the lead in, read the manual and crucially I have the car back.

I can confirm the car DOES runs on LPG, I can hear and see from the indicator (amber) its working. Cut-over back to petrol comes with a slight hesitation. Idle is too low at 500 rpm and the running generally on LPG is not as smooth as petrol. I presume I need to calibrate the Leo, but struggling with knowing what to put the settings at.

Also noticed that the O2 sensor reads at idle (on the Leo software) but goes to "0" when I accelerate.

Would appreciate any advice on calibrating.

[LPGC]

Just the one Leonardo ECU?

1 Leo driving two stepper motors is not a good idea. The steppers are likely to go out of sync and cause problems with mixture imbalance.

This is what I was getting at before...

I can confirm the car DOES runs on LPG, I can hear and see from the indicator (amber) its working. Cut-over back to petrol comes with a slight hesitation. Idle is too low at 500 rpm and the running generally on LPG is not as smooth as petrol. I presume I need to calibrate the Leo, but struggling with knowing what to put the settings at.

Also noticed that the O2 sensor reads at idle (on the Leo software) but goes to "0" when I accelerate.

Would appreciate any advice on calibrating.

I wouldn't attempt to set it up with 2 reducers, 2 stepper motors, 2 mixers and one Leo. Depending how it is installed you could end up with correct mixture on one bank and very wrong mixture on the other, or maybe lambda showing correct but both banks getting an incorrect mixture.

But here's what you can try for the moment without changing parts / piping etc....

If the idle is too low this may be due to incorrect mixture at idle, you didn't mention what Lambda does at idle? If the Lambda is 0 under load then the engine is running lean under load.

Go into the 'Display Parameters' screen. In the 'actuator' part there is an arrow which shows the stepper position, the higher up the arrow the more open the stepper motor. With a low lambda voltage the arrow will move up. It idle the arrow (and hence stepper motor) can only move within the range of the idle bar. Ditto off idle and the off idle bar. If the arrow is restricted by a bar then to get an idea of what adjusments you'll need to make at the reducer(s): Go into the 'Optional configurations' screen, 'actuator tab and change the four numbers (idle / off idle / opening / closing) to 255. Go back to the 'Display parameters' screen. Does the lambda flick properly under all idle and driving conditions? If not then you'll need to adjust the reducer(s) until they do. But this is more complicated in your case because you have 2 reducers and 2 steppers, so depending how it is set up there may be no way of knowing if one bank is rich and the other lean...

When does it 'cut over back to petrol'? Have a look at the other tabs in the 'Optional configurations' screen: It shouldn't need to cut back to petrol. The 'Cut off' option doesn't cut back to petrol, you can set where the stepper moves to at low load above a certain rpm (over-run condition), can prevent backfires due lean mixture on the over-run by moving stepper to a high position, or if it doesn't backfire you can save fuel on over-run by moving stepper to a near closed position... But these only work if the TPS is reading properly. Would disable all cut-off options for the time being.

Simon
www.Lpgc.co.uk

[MackV12]

Simon,

Would I have 1 Leo driving 2 reducers, 2 steppers etc, etc - no, agreed. I would love to have a multipoint, sequential injection system, but I am not holding my breath for Santa . My plan is to see if I can get what I have got working properly first, thanks to the input from this forum I can confirm the LPG is working, to some degree.

I got the car back yesterday and the engine is still missing when it gets hot - which is what it went in for 4 weeks ago. If the car does not run properly on petrol, it is not surprising that is not running well on LPG.

Ok, on to your first question, at idle the O2 (Lambda?) is flickering slightly, similar to petrol.

I flicked the optional/actuator/idle/off idle/open/close setting to 255. It did not seem that the O2 sensor was flickering more, but whether it was appropriate flickering I am not sure. Pretty sure the reducers need adjusting, but until I get the mis-fire sorted when the engine is hot, I am stuck, again....

[Gilbertd]

I'll start by warning you that it's very doubtful you'll be able to get what you have working properly. You have one Leo taking a signal from one lambda sensor in the exhaust downpipe on one bank. It is then adjusting the stepper to get a correct mixture according to the one lambda sensor it is reading. Now it might be able to get the mixture correct on that bank but unless you have two perfectly matched reducers, then it is anyone's guess what the mixture is like on the other one. Even if the lambda sensor is after the exhaust pipes merge so it is seeing the average of both banks you could still have one bank stupidly rich and the other stupidly weak.

I appreciate that a multipoint for a V12 is not going to be cheap, but to get it working properly, and not risk damaging the engine by running it with the mixture way out, your cheapest option is going to be to buy a second Leo so you have control over both banks.

[MackV12]

The message from this Forum is clear, the current system is not fit for purpose. So I see 3 options:

1. Chuck the lot/do not use it - No outlay, but with 2k miles a year, LPG saving lost would be £250 a year.
2. Patch it up with another Leo (then I would have 1 per bank) and reconfigure the existing wiring and tune it. Potentially cheap option.
3. Other than the tank/filler, start again.

Gut feel is option 2 or 3.

Fixing the top water hose tonight and then onto the hot mis-fire.....

[rossko]

Option 1A: get the existing setup working as well as you can, you can always add a second leo later. This will allow you to ascertain/cost if you've got goosed reducer(s), mixer sizing issues etc. Almost certainly you'll discover why those restrictors were fitted ...

It will be worth spending some time studying how the lambda sensor works on petrol under varying conditions, so you know what you are trying to acheive.

Don't get me wrong, it would be the sweetest thing on injection but you are talking big money simply to cover 12 cylinders. It will be an arse to get right on mixers, so you should value your own time into this; or the appeciation of a challenge completed!