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 Post subject: Spark plugs forLPG
PostPosted: Sat Sep 24, 2016 6:59 pm 
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Getting a misfire fault code re cylinder 3 on my Vauxhall Zafira ( fitted with top Prins system in 2012). I am hoping that a new coil pack will do the trick ( it's time for a replacement anyway) and I am going to replace the spark plugs at the same time. I have ordinary Bosch Super in there at the moment but was wondering whether the LPG requires different or better spark plugs? Also how long should the coil pack replacement take me - I am not a mechanic !


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 Post subject: Re: Spark plugs forLPG
PostPosted: Sun Sep 25, 2016 3:30 pm 
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Still the same issue as on this thread? http://www.lpgforum.co.uk/viewtopic.php?f=28&t=14134&p=109365#p109365

I'd go for same model plugs that previously gave good results... Did it ever run without misfires with the Bosch plugs fitted?

Time to change the coil pack is zero if you're changing the plugs, it has to come off to get to the plugs anyway. Only a few minutes job to get the coil pack off, just a few easily accessible torx headed bolts to remove and wiring connector to disconnect before lifting it off.

Simon

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 Post subject: Re: Spark plugs forLPG
PostPosted: Tue Sep 27, 2016 3:14 pm 
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LPGC wrote:
Still the same issue as on this thread? http://www.lpgforum.co.uk/viewtopic.php?f=28&t=14134&p=109365#p109365

I'd go for same model plugs that previously gave good results... Did it ever run without misfires with the Bosch plugs fitted?

Time to change the coil pack is zero if you're changing the plugs, it has to come off to get to the plugs anyway. Only a few minutes job to get the coil pack off, just a few easily accessible torx headed bolts to remove and wiring connector to disconnect before lifting it off.

Simon


Jeez - you are right Simon. I totally forgot that I posted about this in July. Yes - same problem. The real noise seems to come from the back end of the exhaust rather than the bonnet area ? I had the same problem over in Turkey last year - took it to a garage who is an approved Prins installer.( checked out with Prins in Holland). All he did was test each cylinder and fitted a new set of plugs - he said that the previous plugs were the wrong type ! ( fitted by local Vauxhall garage). It solved the problem and I have driven back from Turkey since then and done another return trip to Turkey since then.
I am no mechanic and a local lad will fit the coil pack for £40 - but I watched the Turkish mechanic whip off the cover in no time and I would be better off just buying the appropriate tool to get the torx bolts off and do it myself - if it as simple as you describe lol. Anyway I have bought the Delphi coil pack and I know mechanics differ as to what their favourite brand of plug is - usually NGK by the way rather than Bosch or Denso. That was the reason for my question whether one in particular was better for LPG purposes.


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 Post subject: Re: Spark plugs forLPG
PostPosted: Tue Sep 27, 2016 6:03 pm 
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Joined: Wed Sep 29, 2010 5:01 pm
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Location: Yorkshire
Should only cost a couple of quid for the torx socket, as easy to remove as the few mins it took the mechanic would suggest!

Different plugs recommended for different model Zafira engines (model of engine depending on year), usual LPG advice is NGK but some model Zafira engines like the original fit Bosch plug much better, especially on LPG. I've fitted NGK in Zafiras where Bosch was recommended with poor results so had to remove them to fit Bosch. Again would advise the same plugs you know have worked well.

Simon

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Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


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 Post subject: Re: Spark plugs forLPG
PostPosted: Tue Sep 27, 2016 8:15 pm 
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linsdav8284 wrote:
LPGC wrote:
Still the same issue as on this thread? http://www.lpgforum.co.uk/viewtopic.php?f=28&t=14134&p=109365#p109365

I'd go for same model plugs that previously gave good results... Did it ever run without misfires with the Bosch plugs fitted?

Time to change the coil pack is zero if you're changing the plugs, it has to come off to get to the plugs anyway. Only a few minutes job to get the coil pack off, just a few easily accessible torx headed bolts to remove and wiring connector to disconnect before lifting it off.

Simon


Jeez - you are right Simon. I totally forgot that I posted about this in July. Yes - same problem. The real noise seems to come from the back end of the exhaust rather than the bonnet area ? I had the same problem over in Turkey last year - took it to a garage who is an approved Prins installer.( checked out with Prins in Holland). All he did was test each cylinder and fitted a new set of plugs - he said that the previous plugs were the wrong type ! ( fitted by local Vauxhall garage). It solved the problem and I have driven back from Turkey since then and done another return trip to Turkey since then.
I am no mechanic and a local lad will fit the coil pack for £40 - but I watched the Turkish mechanic whip off the cover in no time and I would be better off just buying the appropriate tool to get the torx bolts off and do it myself - if it as simple as you describe lol. Anyway I have bought the Delphi coil pack and I know mechanics differ as to what their favourite brand of plug is - usually NGK by the way rather than Bosch or Denso. That was the reason for my question whether one in particular was better for LPG purposes.
linsdav8284 wrote:
LPGC wrote:
Still the same issue as on this thread? http://www.lpgforum.co.uk/viewtopic.php?f=28&t=14134&p=109365#p109365

I'd go for same model plugs that previously gave good results... Did it ever run without misfires with the Bosch plugs fitted?

Time to change the coil pack is zero if you're changing the plugs, it has to come off to get to the plugs anyway. Only a few minutes job to get the coil pack off, just a few easily accessible torx headed bolts to remove and wiring connector to disconnect before lifting it off.

Simon


Jeez - you are right Simon. I totally forgot that I posted about this in July. Yes - same problem. The real noise seems to come from the back end of the exhaust rather than the bonnet area ? I had the same problem over in Turkey last year - took it to a garage who is an approved Prins installer.( checked out with Prins in Holland). All he did was test each cylinder and fitted a new set of plugs - he said that the previous plugs were the wrong type ! ( fitted by local Vauxhall garage). It solved the problem and I have driven back from Turkey since then and done another return trip to Turkey since then.
I am no mechanic and a local lad will fit the coil pack for £40 - but I watched the Turkish mechanic whip off the cover in no time and I would be better off just buying the appropriate tool to get the torx bolts off and do it myself - if it as simple as you describe lol. Anyway I have bought the Delphi coil pack and I know mechanics differ as to what their favourite brand of plug is - usually NGK by the way rather than Bosch or Denso. That was the reason for my question whether one in particular was better for LPG purposes.
LPGC wrote:
Should only cost a couple of quid for the torx socket, as easy to remove as the few mins it took the mechanic would suggest!

Different plugs recommended for different model Zafira engines (model of engine depending on year), usual LPG advice is NGK but some model Zafira engines like the original fit Bosch plug much better, especially on LPG. I've fitted NGK in Zafiras where Bosch was recommended with poor results so had to remove them to fit Bosch. Again would advise the same plugs you know have worked well.

Simon


thanks again Simon. Mine is 2010 Zafira 1.6 . Havent a clue as to what was in for the first 55k -replaced by Vauxhall dealer during service.I will go for the NGK .


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 Post subject: Re: Spark plugs forLPG
PostPosted: Thu Jan 05, 2017 7:11 pm 
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LPGC wrote:
Should only cost a couple of quid for the torx socket, as easy to remove as the few mins it took the mechanic would suggest!

Different plugs recommended for different model Zafira engines (model of engine depending on year), usual LPG advice is NGK but some model Zafira engines like the original fit Bosch plug much better, especially on LPG. I've fitted NGK in Zafiras where Bosch was recommended with poor results so had to remove them to fit Bosch. Again would advise the same plugs you know have worked well.

Simon

Just an update Simon . Fitted a new coil pack (Delphi) and new spark plugs and touch wood that seems to have sorted the misfire problem. I could have got a much cheaper option but decided to stick with the brand originally fitted.The local Vauxhall agency gave me 3 spark plug options but stressed they were only applicable to Vauxhall LPG conversion /system!!! Surely not !!.
l


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 Post subject: Re: Spark plugs forLPG
PostPosted: Fri Jan 06, 2017 12:28 am 
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Location: Yorkshire
So if only applicable to the (perhaps factory) LPG converted model, how do they reckon these plugs rate against the petrol only variant model rated plugs, if fitted in the LPG model, if, say, the LPG model is only run on petrol?

The difference may be that the LPG rated plugs have an iridium aspect but are otherwise electrically and in terms of temperature the same as the petrol only spec plug. But when I looked into it the LPG spec plugs were the same as the petrol spec plugs.

There is a lot of misinformation generally regarding LPG, don't believe everything! Today a rep from 'Imex' called in on the off-chance hoping to sell me engine rebuilding stuff in the future. I told him I'd probably only built 5 engines up in the past decade. He was surprised because he was under the impression LPG ate engines for breakfast. I was in front with work and didn't mind his turning up at all, we got on great but couldn't do much business! Anyway, he got on about LPG engines running hotter than petrol engines etc, but I tactfully corrected him. I wish LPG did burn hotter than petrol... I keep saying this but again - internal combustion engines make power by heat creating pressure in cylinders which pushes on pistons which turns the crankshaft... If LPG burned hotter than petrol it would mean engines made more power on LPG than on petrol, but, if there is any difference, slightly the opposite is true. However, if any fuel system is setup to run lean or rich, this affects the speed of the burn, which is another factor that will affect heat taken up by components such ad exhaust valves and spark plugs. A lean mixture on any fuel may imply a slower burn, which implies hotter exhaust valves. If we want to weld steel with a MIG welder we must use a shielding gas such as CO2 to prevent oxygen in the air from oxidising the metal in the weld.. without the presence of oxygen we can get steel very hot indeed without affecting it's chemical composition. If we want to cut through steel we might use a cutting torch that has an element (pun?) of excess oxygen in the flame, the oxygen does it's oxygenation thing very well and helps tremendously in cutting the steel. Best not to run a lean mixture, with slower burn and excess oxygen, in any engine on any fuel. Best not to rely on mixture autocalibration facilities that are built into a lot of today's LPG ECU's, best not use done in a day and dodgy installers (that don't know what they're doing) that rely of such ECU facilities because ECU autotune facilities cannot address getting mixture correct at high engine loads. Long time coming to this - No need to swap spark plug heat range, either.

Simon

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Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


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 Post subject: Re: Spark plugs forLPG
PostPosted: Fri Jan 20, 2017 2:22 pm 
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Joined: Mon Jan 16, 2017 11:21 pm
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I tried iridium plugs once... no difference noticed so I went back to lawnmower NGKs at £2 each off ebay, lol.

Ht lead arcing is my main problem, but I'm loath to pay £60 for a set of magnecor leads and find they do similar.


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