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V8 lpg starting problem


wanaron

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Hi

was wondering if anyone might be able to throw some light as to why my 97 v8 Disco 1, with Romano single point lpg system is being a pig to start? has been sweet as a nut until last couple of days( typical,it being Xmas)Whirrs over, plenty of battery power and is firing, even starts briefly. then you hear a definite click and cuts straight out? Could the cold be freezing the system in some way? Had to change over to petrol yesterday morning, still took ages to start, but eventually did. Run it then without any trouble, changed to gas, again run ok. switched her off and parked up for night, but same again this morning? Not got a lot of experience with Lpg, but with the click im getting and cutting out, could it be a solenoid maybe sticking/ freezing? Any help or advice would be greatly appreciated to get round this.

Thank you Wayne

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I have the same system on my Disco. I was told when i bought it that you should start it on petrol as a matter of course. the system uses heat from the engine to assist in the vapourisation of the lpg. This is why the vapouriser is plumbed into the cooling system.

It may be that you have been lucky and the ambient temperature has been high enough for the gas to vapourise on its own up until now. Alternatively it could be that the gas flow is set high enough to allow it to start. I know that I can turn mine up high enough to start after being stood outside overnight in minus fifteen centigrade, but by doing so it would be dumping a heck of a lot of lpg into the system for no reason. If this is the case you should back it off and start on petrol even in the summer. Its a small price to pay for the saving you will see in your lpg usage.

HTH

Paul

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Thanks Paul,

helps to know there is someone out there with the same system. as i have said i am a novice when it comed to Lpg, have heard of this starting on petrol before, my limited understanding is that it starts on petrol (briefly)and when you rev it a bit it changes over to gas. so what you are saying is warm the engine on petrol? always? this morning th vaporiser was slightly iced up, gotta hairdyer on it and it started, revved it and it run sweet after that. interesting that you mention turning up or down the gas flow on the Romano system, which knob or screw actually does that?

very early in the new year gonna be looking at getting the lpg system serviced. im told once a year is needed. whats your thoughts and experiences of this mate.

cheers n hope you avin good Xmas Wayne

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Thanks Paul,

helps to know there is someone out there with the same system. as i have said i am a novice when it comed to Lpg, have heard of this starting on petrol before, my limited understanding is that it starts on petrol (briefly)and when you rev it a bit it changes over to gas. so what you are saying is warm the engine on petrol? always? this morning th vaporiser was slightly iced up, gotta hairdyer on it and it started, revved it and it run sweet after that. interesting that you mention turning up or down the gas flow on the Romano system, which knob or screw actually does that?

very early in the new year gonna be looking at getting the lpg system serviced. im told once a year is needed. whats your thoughts and experiences of this mate.

cheers n hope you avin good Xmas Wayne

I always start mine with the control switch for the lpg switched to petrol. I then drive for about a mile or so in the summer and a bit longer in the winter. This allows the engine to get up to temp and the lpg will then vapourise much more efficiently.

The amount of lpg flowing in is controlled by the black knob on the top of the unit. From memory you screw it in to decrease and out to increase the flow. To set it up properly you need the engine to be at operating temperature. Back the flow off slowly until the engine begins to hunt and feels like it's stalling, then screw back out again a quarter of a turn. Take it for a drive and see how it runs. If it feels rough open up the control another quarter turn until you get a smooth running engine. You shouldn't need to adjust it more than once or twice. As an aside, as mine is an auto I set it up with the box in D as that is where it spends most of its time. (And before the H&S police turn up, there was somebody sat with their foot oon the brake). If everything is set up correctly you should find it quite hard to start from cold on lpg, as soon as it's up to temperature flick the switch and blip the revs over 2000 and it should run sweet as a nut.

I may be teaching my grandmother to suck eggs, but make sure that you have the correct plugs and leads. The Rover V8 is VERY particular about this, they don't like cheap ones, but they don't like fancy expensive ones either. Just stick to what's in the book and you'll not go far wrong.

As for servicing, once a year sounds good. Try and get it done a week or so before your MOT is due. It is actually possible for it to fail emissions on lpg if there is a problem with the system. Ask me how I know.....:angry:

I'm no expert, and there are far more experienced people on here than me. But the above has worked for me.

HTH,

Paul

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My old man had a Lexus Ls 400 running on LPG and you always had to start and run her for a short while with the control unit set to petrol then switch to gas when it warmed up a bit, it would start on gas but would cut out as you described unless it was very warm outside. The way we used to do it was start on petrol keeping an eye on the temp gauge and as soon as it started to move you could 'switch over' and she always ran fine then.

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My old man had a Lexus Ls 400 running on LPG and you always had to start and run her for a short while with the control unit set to petrol then switch to gas when it warmed up a bit, it would start on gas but would cut out as you described unless it was very warm outside. The way we used to do it was start on petrol keeping an eye on the temp gauge and as soon as it started to move you could 'switch over' and she always ran fine then.

Thanks Paul and Trevor,

any help is appreciated. havent had any more problems starting her since the weather warmed up. But very interesting that you both say need to get some warmth into her before switching to gas.

Im beginning to think that my Disco may be set a bit rich gas wise from what you are saying. Its a fact that it doesnt return as well mpg wise compared to a friends which is the same (v8i auto on singlepoint lpg.) prob get the new year celebrations behind me, then take a closer look as u say back off the flow. have heard that it is imperative to have good plugs and leads with the v8, in fact was one of the first things i did when getting her. using NGK plugs which seem to perform well.

Have a good new year ( to all) and will keep posting as to developments.

thanks Wayne

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Just to throw a spanner in the works...

I have run LPG for a few years now and always start on LPG from cold. Just recently I installed a wideband lamda sensor and I did find that it was runnning too rich, however it will still start from cold now when set to run at a (Petrol) AFR of 14:1. However in this state of tune it does need some choke for a minute or 2, this does not affect the mixture when on LPG but does raise the idle speed.

The only time I have had any issues with vap freezing have been last year when we had 20 inches of snow on the ground (very cold), the second time was this year when my vap froze- this was down to my antifreeze not being up to strength as I had been topping off the coolant with tap water whilst I had been searching for a leak.

In terms of plugs I have been used NGK's, Champions and Densos all with no problems- always gapped to the mid range of the LR specs.

As far as leads are concerned, don't buy expensive ones- just stick to genuine and route them properly. Invest in some extra clip things to separate them if necessary. Keep them clean and avoid them crossing or touching anything.

If using a distributor use a genuine cap and rotor arm.

Have fun with the v8 :D

*edit- your first post mentions you hear a click and then it dies sometimes. Sounds like the solenoids are closing.

Most LPG systems are setup so that they shutdown the gas when the engine is not running. The LPG system has a feed from the negative terminal of the coil or may have a lead wrapped around an HT lead for the signal to indicate engine is running. On my system it is currently set to cut the gas off after 3 seconds. I guess if this signal is not being seen by LPG switch it may cut the gas off.

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Just to throw a spanner in the works...

I have run LPG for a few years now and always start on LPG from cold. Just recently I installed a wideband lamda sensor and I did find that it was runnning too rich, however it will still start from cold now when set to run at a (Petrol) AFR of 14:1. However in this state of tune it does need some choke for a minute or 2, this does not affect the mixture when on LPG but does raise the idle speed.

The only time I have had any issues with vap freezing have been last year when we had 20 inches of snow on the ground (very cold), the second time was this year when my vap froze- this was down to my antifreeze not being up to strength as I had been topping off the coolant with tap water whilst I had been searching for a leak.

In terms of plugs I have been used NGK's, Champions and Densos all with no problems- always gapped to the mid range of the LR specs.

As far as leads are concerned, don't buy expensive ones- just stick to genuine and route them properly. Invest in some extra clip things to separate them if necessary. Keep them clean and avoid them crossing or touching anything.

If using a distributor use a genuine cap and rotor arm.

Have fun with the v8 :D

*edit- your first post mentions you hear a click and then it dies sometimes. Sounds like the solenoids are closing.

Most LPG systems are setup so that they shutdown the gas when the engine is not running. The LPG system has a feed from the negative terminal of the coil or may have a lead wrapped around an HT lead for the signal to indicate engine is running. On my system it is currently set to cut the gas off after 3 seconds. I guess if this signal is not being seen by LPG switch it may cut the gas off.

not sure what to do now, not had any starting problems since that couple of really cold days. i believe as i have said that its starts on petrol, then when you rev her it changes to gas. my missus who uses the v8 to get to the horses has got into the habit of letting the motor idle 4 a while before pulling away. if you dont let it idle( n warm a little) it has a tendency to cut out when not got very far at all. however if do the little warm up it runs great.

interesting that you mention antifreeze being weak.As ive said not got a lot of experience with LPg, so are u saying that the antifreeze passes thru the vaporiser then?

The advice on the leads cap n rotor seems to be shared by all v8 owners and is duly heeded.

i think the solenoid click i was hearing, is as you say the gas cutting off because of the froze up vap.

good these v8s thou aint they.

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