Lpg - Some Issues

[Ifty]

Thanks Bluesman - appreciate the offer. I'll let you know how I get on

Mike

Mike

g

Are you still having problems,

i had my LS430 converted last november and have done over 13000 miles. Idid have a warning light on which the installer sorted in about 10 mins. His name is Nuzza (Bham auto gas) 0121 326 7171. Call him for advice.

Ifty

[mikesands]

Thanks Bluesman - appreciate the offer. I'll let you know how I get on

Mike

Mike

g

Are you still having problems,

i had my LS430 converted last november and have done over 13000 miles. Idid have a warning light on which the installer sorted in about 10 mins. His name is Nuzza (Bham auto gas) 0121 326 7171. Call him for advice.

Ifty

Sorry Ifty - just spotted this. Yes I am still having problems. We have swapped the evaporator and the Romano ECU from a car (his car) that was giving reasonable consumption on a run (25mpg on gas. But it's still the same on mine. Light comes on and consumption is 21mpg. I guess it's got to be down to the injectors?

We can reset the system and the light goes off briefly but after about 3 start-ups, it comes back on.

Might give you guy a ring soon.

Thanks

Mike

[ManicMark]

Hi Mike ive read through your posts (sorry you are haveing problems) I think after all this time trying to sort it out you should approach your mechanic friend with the idea of stripping all the components & electrics out & starting again with a fresh conversion,

It seems like it would be the quick & easy option. Best of luck Mark

[Bluesman]

Thanks Bluesman - appreciate the offer. I'll let you know how I get on

Mike

Mike

g

Are you still having problems,

i had my LS430 converted last november and have done over 13000 miles. Idid have a warning light on which the installer sorted in about 10 mins. His name is Nuzza (Bham auto gas) 0121 326 7171. Call him for advice.

Ifty

Sorry Ifty - just spotted this. Yes I am still having problems. We have swapped the evaporator and the Romano ECU from a car (his car) that was giving reasonable consumption on a run (25mpg on gas. But it's still the same on mine. Light comes on and consumption is 21mpg. I guess it's got to be down to the injectors?

We can reset the system and the light goes off briefly but after about 3 start-ups, it comes back on.

Might give you guy a ring soon.

Thanks

Mike

Hi Mike.

You poor ol thing, I had hoped as you hadnt posted that it had been sorted.

I do hope you get a solution so you can enjoy quality motoring at an economic price.

Good luck Mike

[Ifty]

Mike

I am having my first LPG service this friday after 13000 trouble free miles. I will mention to Nuzzar about your problems ans see what he says,

Ifty

[mikesands]

That would be good. We are swapping the injectors next week.

Thanks

Mike

[Ifty]

Hi Mike

I had my 12000 mile LPG service today from Birmingham Autogas. It cost £35 and they stamped the LPG service book. They upgraded the software so when engine is warm and I start it, it will start with gas so I dont have to wait for 30 secs.

I spoke to them about your problem and he said without looking at the car with his diagnostics it would be difficult to say but he said re look at the fuel trims (or something like that) to start with. Maybe that will help.

regards

Ifty

[mikesands]

update - we changed all the injectors from his car to mine. Took him quite a while, but it has made no difference, the engine warning light still comes on. Worse than that now the VSC light is coming on

Anyone any ideas?

Mike

[Bluesman]

update - we changed all the injectors from his car to mine. Took him quite a while, but it has made no difference, the engine warning light still comes on. Worse than that now the VSC light is coming on

Anyone any ideas?

Mike

Mike I am sorry you are still having problems and even more from the sound of it.

I dont know what to add to the advice I have already given you but to say the longer you leave it the weaker your legal position will become. Good luck.

Mike

[Ifty]

Hi Mike

The VSC light is not a problem to take off. mine came on and he connected 2 wires which took it off. All I can suggest is that you give Nuzzar a call as I am sure he can sort it out for you. The rest is upto you. He updated my software on my car and its still running A1 after 16000 miles.

Regards

Ifty

[mikesands]

Thanks Ifty,

My guy replaced all the injectors from my car with the ones on his. It seems to have made some improvement. My guess is that it's now only 10 or 12% down on the MPG from petrol, but I would like to do a long motorway run to double check. Engine warning and VSC lights still on though. He's had it again today so hopefully he will have made some progress.

Mike

[John N]

Thanks Ifty,

My guy replaced all the injectors from my car with the ones on his. It seems to have made some improvement. My guess is that it's now only 10 or 12% down on the MPG from petrol, but I would like to do a long motorway run to double check. Engine warning and VSC lights still on though. He's had it again today so hopefully he will have made some progress.

Mike

Mike

I had a lot of trouble with the two previous cars I had converted to LPG, the answers to these questions may help identify your problem.

Did you find out which fault codes were being triggered when the engine warning light came on?

Is the engine warning light on as soon as the ignition is turned on?

If you leave the car running on petrol with the LPG system turned off, and you start and stop the engine 3 or 4 times does the engine warning light go out and stay off until you use gas again? ( The LS430 will often turn off the engine warning light if a fault does not recur in 3 or 4 runs.)

If you do manage to clear the engine warning light and you change back to LPG at what point does the warning light come on again? As soon as the engine changes over to LPG, when it is on a normal light throttle, accelerating hard, on the over-run or idling?

Also is there any hint of a misfire or hesitation as the engine switches from petrol to LPG, or back from LPG to petrol? If there is, it indicates a cross connection in the gas valve wiring, and you may have some gas valves controlled by the wrong petrol injectors. (This happened to me, the engine would run OK on LPG or petrol but misfired on changeover.)

The set-up software for the LPG system should allow the installer to monitor the gas temperature when the system is running. The installer should have checked the evaporator was heating the gas to the right temperature when he set the system up in the garage, but the evaporator has to work much harder out on the open road. You need to connect the computer to the system and do a test run to check the evaporator is keeping the gas at the correct temperature when the engine is working hard on the open road. (This also happened to me, the water supply to the evaporator had not been connected properly and could not evaporate enough gas when the engine had to work hard.)

I've also looked into the question of the MPG you get on gas compared to petrol. There is lots on this subject on the web, and there appears to be a consensus that you get 10% to 20% less mpg on gas. The reason is that a litre of LPG contains less energy (calories) than a litre of petrol, so you have to burn more to get the same power. The people who are trying to sell you gas conversions appear to conveniently forget this and simply compare LPG and petrol prices, then claim you will make a 50% saving. In reality if your mpg drops by 20% you will only make a 33% saving, but even this represents a very good investment if you do over 10k a year.

Hope you solve your problems soon.

John N

[mikesands]

I will try and insert answers within your text John - thanks for spending the time by the way

Mike

I had a lot of trouble with the two previous cars I had converted to LPG, the answers to these questions may help identify your problem.

Did you find out which fault codes were being triggered when the engine warning light came on?

**** Yes it is the oxygen sensor warning - the later VSC light is saying motion sensor ****

Is the engine warning light on as soon as the ignition is turned on?

**** yes if it's been running on gas ****

If you leave the car running on petrol with the LPG system turned off, and you start and stop the engine 3 or 4 times does the engine warning light go out and stay off until you use gas again? ( The LS430 will often turn off the engine warning light if a fault does not recur in 3 or 4 runs.)

*** yes all problems with the engine warning light disappear after 3 or 4 starts on petrol. And consumption returns to pretty good 22 round town 30 on a run. The VSC light does not go off though *****

If you do manage to clear the engine warning light and you change back to LPG at what point does the warning light come on again? As soon as the engine changes over to LPG, when it is on a normal light throttle, accelerating hard, on the over-run or idling?

**** It only begins to come on after 3 or 4 starts on gas, then I can't say what brings it on but yesterday it did come on whilst driving rather than on start-up****

Also is there any hint of a misfire or hesitation as the engine switches from petrol to LPG, or back from LPG to petrol? If there is, it indicates a cross connection in the gas valve wiring, and you may have some gas valves controlled by the wrong petrol injectors. (This happened to me, the engine would run OK on LPG or petrol but misfired on changeover.)

**** can't say I've noticed ... but I will change over tonight and pay particular attention ****

The set-up software for the LPG system should allow the installer to monitor the gas temperature when the system is running. The installer should have checked the evaporator was heating the gas to the right temperature when he set the system up in the garage, but the evaporator has to work much harder out on the open road. You need to connect the computer to the system and do a test run to check the evaporator is keeping the gas at the correct temperature when the engine is working hard on the open road. (This also happened to me, the water supply to the evaporator had not been connected properly and could not evaporate enough gas when the engine had to work hard.)

***** This looks useful, and I will pass it on. However he seemed clued up on the evaporator as he told me how critical it is to keep the coolant system in good nick. Mind you the first evaporator he fitted made some irritating whining noises so he changed it for the one that was on his car and the noises disappeared. However the engine warning light was coming on with the original (noisy) evaporator.******

I've also looked into the question of the MPG you get on gas compared to petrol. There is lots on this subject on the web, and there appears to be a consensus that you get 10% to 20% less mpg on gas. The reason is that a litre of LPG contains less energy (calories) than a litre of petrol, so you have to burn more to get the same power. The people who are trying to sell you gas conversions appear to conveniently forget this and simply compare LPG and petrol prices, then claim you will make a 50% saving. In reality if your mpg drops by 20% you will only make a 33% saving, but even this represents a very good investment if you do over 10k a year.

**** Yes I too have researched it and believe the increase in concumption should be about 15% - in fact when I borrowed his car that's just about what I got. But as of yesterday my consumption round town was 27% worse and on a run around 30% worse. Payback on those figures is a lot longer than I calculated :-( *****

Hope you solve your problems soon.

**** are you running an LPG LS now? ***

John N

[mikesands]

Thanks Ifty,

My guy replaced all the injectors from my car with the ones on his. It seems to have made some improvement. My guess is that it's now only 10 or 12% down on the MPG from petrol, but I would like to do a long motorway run to double check. Engine warning and VSC lights still on though. He's had it again today so hopefully he will have made some progress.

Mike

By the way - I should correct this. When I checked the round town consumption on Tuesday it was 15.9mpg. I think the previous fill-up must have included some longer motorway runs than I thought.

Mike

[mikesands]

JohnN - no detectable twitch misfire or jerk when switching between gas or petrol or back again.

Thanks

Mike

[John N]

JohnN - no detectable twitch misfire or jerk when switching between gas or petrol or back again.

Thanks

Mike

Hi Mike

First I don't think your VSC problem is related to the LPG conversion, unless a sensor or its' lead has been disturbed by the work you have had done.

If you cannot detect any twitch on change-over it indicates the system has been wired up correctly, and it is actuating the right gas valves at the right time.

The oxygen sensor fault code that triggers the engine warning light indicates that at some point the LPG system is getting the fuel/air ratio wrong. This can mean that the 'mapping' needs adjusting, but if it can take 3 or 4 runs on gas to bring the engine warning light on after it has been cleared the error may only be transient and not a significant problem. (Other people with LPG conversions appear to be happy to live with this problem if the car runs OK on gas.)

On the other hand fuel/air ratio problems can be caused by the LPG evaporator not supplying gas to the engine at a constant pressure. This can be because it is not evaporating the liquid gas or controlling the gas pressure properly. Get the gas temperature and pressure checked out on the road, it should be able to keep the gas at the recommended pressure.

Getting the software mapping spot-on is not as critical as many people think because the system is self correcting. The map is the ratio between how long the gas valves open compared to how long the petrol injectors would open at different engine speeds. The LPG system then looks at how long the engine ECU is telling the petrol injectors to open for, then it opens the gas valves instead for the time needed for the equivalent amount of gas. If it gets the timing slightly wrong the oxygen sensor will detect the engine running rich or lean and the engine ECU will correct the petrol injector timing which in turn corrects the gas valve timing. The engine ECU can adjust the fuel/air ratio by quite a large amount but if it reaches the adjustment limit and the oxygen sensor is still not happy it assumes the oxygen sensor is faulty and trips the engine warning light.

Non of the problems I had with my previous LPG conversions were due to the software mapping, they were caused by crossed wiring, lack of hot water to the evaporator and faulty gas valves. Don't assume it's a complicated software problem, check the simple stuff first.

In answer to your last question, yes I had my LS430 converted a couple of months ago by Worsley Autogas, just outside Manchester. I had to think long and hard about it after the problems I'd had with previous conversions. But I was finally persuaded by the post put up by 'Parrot of Doom' and other peoples comments on the BRC system they supply. Up to now the system has been faultless but my town mpg is down by 20% from 20 to 16 mpg. Still it represents a 33% saving on petrol costs and should pay for itself in just over a year. ( You don't get that return from an ISA ! )

John N

[mikesands]

Thanks for taking the time again John. Yes I think me and my engineer realised that the VSC problem is not actually caused by the conversion even though it came on while he was trying to cure the engine light issue. He's borrowing another piece of kit to clear it.

Now .... your mention of pressure is interesting, because often the engine light goes off when the mileage reached 150 miles since full. So that's probably about half a tank. I was getting 22.3 on petrol on local runs but 16mpg on gas. That's not acceptable really and on 17ooo miles per year is a payback of over 3 years.

We'll take a closer look at what the evaporator is up to.

Thanks

Again

Mike

[John N]

Thanks for taking the time again John. Yes I think me and my engineer realised that the VSC problem is not actually caused by the conversion even though it came on while he was trying to cure the engine light issue. He's borrowing another piece of kit to clear it.

Now .... your mention of pressure is interesting, because often the engine light goes off when the mileage reached 150 miles since full. So that's probably about half a tank. I was getting 22.3 on petrol on local runs but 16mpg on gas. That's not acceptable really and on 17ooo miles per year is a payback of over 3 years.

We'll take a closer look at what the evaporator is up to.

Thanks

Again

Mike

Mike

A quick suggestion: The LPG set-up computer should be able to reed the gas pressure when it is connected to the system. Connect it up and do a test run when the gas tank is nearly empty, then fill the tank and do another test run. There should not be a significant difference in the gas pressure between a full or nearly empty tank. The job of the evaporator/pressure regulator is to keep the gas pressure steady at the LPG systems recommended working pressure.

You can usually adjust the pressure regulator easily, but if you do you will need to re-calibrate the system.

Best of luck.

John N

[AKY-B]

Had my LS430 (2001) converted back in March but the consumption is pretty terrible compared with petrol. I decided to run the gas empty and check what the car does on a run on petrol (teesside down to London via A1). I got 31.8mpg which incidentally was better than the fuel computer was saying. This contrasts with the 21.3 mpg I got on LPG on a trip to cardiff and 21.7 on the return.

Round town I am definitely getting about 17mpg on gas and the fuel computer was previously showing 22.3 mpg on petrol.

The garage that fitted the LPG have had it back two or three times for 'recalibration' but it doesn't seem to make any difference.

I think the LPG mapping is out - particularly as the engine warning light comes on with LPG but not if I revert to petrol.

The garage want to remap but say that this would not be with anything provided from Romano. Does anyone know where I could get suggested maps for an LS430 to suit the Romano multipoint?

I'm nervous about them leaning it off and wrecking the engine.

Mike

HI sorry to hear about your problems. you definitely have a problem.! i get 35-40 in money terms on mine but i have a prins multi point system.any decent installer should fix it.My linktry these guys.they do mobile servicing and repairs

[mikesands]

Thanks for the link AKY-B 35-40 mpg in money terms sounds like 19.8mpg on gas .... is that around town?

Mike

[Mybikesacx500]

Thanks for the link AKY-B 35-40 mpg in money terms sounds like 19.8mpg on gas .... is that around town?

Mike

My MkII has single point injection LPG and I get 18 to 20 on long runs, but I keep it below 70. Saying that, if it's all around town, I get 13.....

[nicenic61]

Mike etc., bought a MK4 with Stefanelli lpg conversion a few months ago, no paperwork, no idea when it was last serviced and it runs very rough when cold and on petrol, definitely needs a service. Just passed it's MOT though. I get 16-17 on gas around town usually without the aircon, and on a long run to Newcastle from Nottingham I got 25 on gas without much use of aircon. Hopefully this will improve when I get round to getting it serviced. Not much help for your problem but it gives you an idea of mpg ....

Nick

[mikesands]

Mike etc., bought a MK4 with Stefanelli lpg conversion a few months ago, no paperwork, no idea when it was last serviced and it runs very rough when cold and on petrol, definitely needs a service. Just passed it's MOT though. I get 16-17 on gas around town usually without the aircon, and on a long run to Newcastle from Nottingham I got 25 on gas without much use of aircon. Hopefully this will improve when I get round to getting it serviced. Not much help for your problem but it gives you an idea of mpg ....

Nick

Nick - that is useful thanks. My 17mpg 'round town' is not really round town it's mainly a 6 mile run to work on the A19. So I would expect better. Also I would be very happy with 25mpg on a motorway run but haven't bettered 21mpg yet.

Mike

[Parrot of Doom]

If your journey is only 6 miles then for most of that time I would imagine the engine will be running rich. You'll never see good mpg in that situation.

[mikesands]

If your journey is only 6 miles then for most of that time I would imagine the engine will be running rich. You'll never see good mpg in that situation.

Possibly, but it's got to be better than 6 miles of stop start at road junctions and traffic lights so I would expect better than purely urban round town driving. Also when I top up it's usually as per last night 63 litres of LPG and 3.7 litres of petrol (250 miles by the way), so it's getting plenty of chance to get past the initial start up period.

Mike