Omega Owners Forum
Chat Area => General Car Chat => Topic started by: Robski on 09 March 2010, 11:19:45
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Right here goes,I have just had 3ltr cams and inlet plate fitted to my 2.5 since they have been fitted if I get giddy with the right foot the LPG shuts off and starts running on petrol,so visited a LPG installer to see why the gas keeps shutting off told him what had been done and he says that the gas is underfueling due to the 3ltr cams and that I need to have a remap of the petrol to suit the cams as the gas reads from petrol ecu.I spoke to DLK yesterday and he told he that was *ollox regarding remapping but was not too sure regarding the gas any help would be appreciated :y :y :y
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Right here goes,I have just had 3ltr cams and inlet plate fitted to my 2.5 since they have been fitted if I get giddy with the right foot the LPG shuts off and starts running on petrol,so visited a LPG installer to see why the gas keeps shutting off told him what had been done and he says that the gas is underfueling due to the 3ltr cams and that I need to have a remap of the petrol to suit the cams as the gas reads from petrol ecu.I spoke to DLK yesterday and he told he that was *ollox regarding remapping but was not too sure regarding the gas any help would be appreciated :y :y :y
No expert on LPG setups .. but my initial guess is that the LPG can't supply enough gas when you are "giving it large" .. probably just needs the vapouriser pressure tweaking up a bit .. but it could be that the injectors are not man enough for the job and need drilling out a wee tad.
A lot will depend on the type of system you have, what injectors are fitted, and what software is used to control it.
There are some pretty good LPG experts on here .. I'm sure one will pass by soon and prove me totally wrong . !!!
:)
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Yep, it is "ollox" because the petrol ECU bases its' fuelling on what airflow the MAF sensor is seeing. A small increase from a cam change it will cope with without any remapping.
It could be, however, that the LPG system is not able to cope with the increased fuel demand. The question is: why does it revert to petrol? Normally due to low vapour pressure which could mean the system can't deliver fuel fast enough or it could also be down to (or contributed by) a partially blocked filter or vapouriser.
The petrol side of things certainly doesn't need any attention though. :y
Kevin
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Yep, it is "ollox" because the petrol ECU bases its' fuelling on what airflow the MAF sensor is seeing. A small increase from a cam change it will cope with without any remapping.
It could be, however, that the LPG system is not able to cope with the increased fuel demand. The question is: why does it revert to petrol? Normally due to low vapour pressure which could mean the system can't deliver fuel fast enough or it could also be down to (or contributed by) a partially blocked filter or vapouriser.
The petrol side of things certainly doesn't need any attention though. :y
Kevin
Cheers Kevin thats what DLK was saying regarding the petrol but wasnt sure regarding gas,my LPG system is a BRC sequential :y :y
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Petrol ECU as already said, needs no changing.
The LPG might not e delivering the gas requried and is doing the correct thing b resorting to petrol at uber revs and wide throttle, I assume it detects max LPG injector duration and reverts based on that.
Sounds to me like you need to avoid this guy like the plague as he clearly is lacking a good grasp of the basics of even the LPG operation let alone the Petrol one!!
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Petrol ECU as already said, needs no changing.
The LPG might not e delivering the gas requried and is doing the correct thing b resorting to petrol at uber revs and wide throttle, I assume it detects max LPG injector duration and reverts based on that.
Sounds to me like you need to avoid this guy like the plague as he clearly is lacking a good grasp of the basics of even the LPG operation let alone the Petrol one!!
I take it you mean the gas man an not DLK ;D ;D
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I take it you mean the gas man an not DLK ;D ;D
Probably wise to avoid both, for different reasons. ;)
The former'll completely Roger your car if given half the chance and ... ::)
;)
kevin
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I take it you mean the gas man an not DLK ;D ;D
Probably wise to avoid both, for different reasons. ;)
The former'll completely Roger your car if given half the chance and ... ::)
;)
kevin
Im aware of DLK best to not let him pass behind you ;D ;D ;D
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BRC is one of the better makes of LPG... Should be able to cope really, especially as the actual difference is not that big in the grand scheme of things ::) ::)
I bet it just want re-mapping, although it may benefit from having the injectors enlarged slightly :y :y
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BRC is one of the better makes of LPG... Should be able to cope really, especially as the actual difference is not that big in the grand scheme of things ::) ::)
I bet it just want re-mapping, although it may benefit from having the injectors enlarged slightly :y :y
Re Mapping is what this bloke mentioned that Rob needed to the tune of £800 :o
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BRC is one of the better makes of LPG... Should be able to cope really, especially as the actual difference is not that big in the grand scheme of things ::) ::)
I bet it just want re-mapping, although it may benefit from having the injectors enlarged slightly :y :y
Re Mapping is what this bloke mentioned that Rob needed to the tune of £800 :o
WTF :o :o :o
It's a 10 minute job at most! :o :o :o
Rob... Does it do it with a full tank of Gas too or just when part used?
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BRC is one of the better makes of LPG... Should be able to cope really, especially as the actual difference is not that big in the grand scheme of things ::) ::)
I bet it just want re-mapping, although it may benefit from having the injectors enlarged slightly :y :y
Re Mapping is what this bloke mentioned that Rob needed to the tune of £800 :o
WTF :o :o :o
It's a 10 minute job at most! :o :o :o
Rob... Does it do it with a full tank of Gas too or just when part used?
£80 a minute sounds very good money then :o
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Right here goes,I have just had 3ltr cams and inlet plate fitted to my 2.5 since they have been fitted if I get giddy with the right foot the LPG shuts off and starts running on petrol,so visited a LPG installer to see why the gas keeps shutting off told him what had been done and he says that the gas is underfueling due to the 3ltr cams and that I need to have a remap of the petrol to suit the cams as the gas reads from petrol ecu.I spoke to DLK yesterday and he told he that was *ollox regarding remapping but was not too sure regarding the gas any help would be appreciated :y :y :y
This is what has happened
You have changed the engine characteristics, it is now around 190bhp, the kist was set up with a 170bhp engine.
At full throttle and high revs the gas injectors cannot open long enough to inject enough gas to run safely, so it drops to petrol.
Would need a little more than a remap, possibly upping the pressure, possibly boring out the LPG nozzles, or setting the kit to drop to petrol at over 5500rpm.
6mm bore pipe seems to have a limit of about 200bhp, hence Kevin using 8mm.
I need to remap mine since recamming, but am tempted to replace the vapouriser as mine is knackered
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Right here goes,I have just had 3ltr cams and inlet plate fitted to my 2.5 since they have been fitted if I get giddy with the right foot the LPG shuts off and starts running on petrol,so visited a LPG installer to see why the gas keeps shutting off told him what had been done and he says that the gas is underfueling due to the 3ltr cams and that I need to have a remap of the petrol to suit the cams as the gas reads from petrol ecu.I spoke to DLK yesterday and he told he that was *ollox regarding remapping but was not too sure regarding the gas any help would be appreciated :y :y :y
This is what has happened
You have changed the engine characteristics, it is now around 190bhp, the kist was set up with a 170bhp engine.
At full throttle and high revs the gas injectors cannot open long enough to inject enough gas to run safely, so it drops to petrol.
Would need a little more than a remap, possibly upping the pressure, possibly boring out the LPG nozzles, or setting the kit to drop to petrol at over 5500rpm.
6mm bore pipe seems to have a limit of about 200bhp, hence Kevin using 8mm.
I need to remap mine since recamming, but am tempted to replace the vapouriser as mine is knackered
Not a problem with your description at all .. I agree with it in fact .. but the OP said he had a BRC Sequential system .. and AFAIK they are fully capable of much higher HP .. I have a BRC Seq on mine and it handles 217 HP without a hitch ...
I just wonder WHICH BRC system he has ... ?? might give us some clues ??
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Right here goes,I have just had 3ltr cams and inlet plate fitted to my 2.5 since they have been fitted if I get giddy with the right foot the LPG shuts off and starts running on petrol,so visited a LPG installer to see why the gas keeps shutting off told him what had been done and he says that the gas is underfueling due to the 3ltr cams and that I need to have a remap of the petrol to suit the cams as the gas reads from petrol ecu.I spoke to DLK yesterday and he told he that was *ollox regarding remapping but was not too sure regarding the gas any help would be appreciated :y :y :y
This is what has happened
You have changed the engine characteristics, it is now around 190bhp, the kist was set up with a 170bhp engine.
At full throttle and high revs the gas injectors cannot open long enough to inject enough gas to run safely, so it drops to petrol.
Would need a little more than a remap, possibly upping the pressure, possibly boring out the LPG nozzles, or setting the kit to drop to petrol at over 5500rpm.
6mm bore pipe seems to have a limit of about 200bhp, hence Kevin using 8mm.
I need to remap mine since recamming, but am tempted to replace the vapouriser as mine is knackered
Not a problem with your description at all .. I agree with it in fact .. but the OP said he had a BRC Sequential system .. and AFAIK they are fully capable of much higher HP .. I have a BRC Seq on mine and it handles 217 HP without a hitch ...
I just wonder WHICH BRC system he has ... ?? might give us some clues ??
Sequent 56 looking at the lpg system info book that was given on install :y
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As far as I know .. the sequent 56 will handle up to 30 kwatts /cylinder with standard injectors - page 32
http://www.remixbg.com/Documentation/Documents/Gazovi%20uredbi/BRC/SEQUENT%20Plug%20&%20Drive/Manuale_Seq_Instal_1_3_en.pdf
now 30 kwatts / cylinder x 6 = 180 kwatts which is 240 HP ... quite a bit more than an Omega 3.2 !!!
so the system "should" handle it ... but I suppose it could have the smaller evaporator ... which would limit it to 26 kwatts/cylinder .. but that is still 26x6 = 156 kwatts = 209 HP ....
unless the evaporator is tired or needs a tweak ???
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As far as I know .. the sequent 56 will handle up to 30 kwatts /cylinder with standard injectors - page 32
http://www.remixbg.com/Documentation/Documents/Gazovi%20uredbi/BRC/SEQUENT%20Plug%20&%20Drive/Manuale_Seq_Instal_1_3_en.pdf
now 30 kwatts / cylinder x 6 = 180 kwatts which is 240 HP ... quite a bit more than an Omega 3.2 !!!
so the system "should" handle it ... but I suppose it could have the smaller evaporator ... which would limit it to 26 kwatts/cylinder .. but that is still 26x6 = 156 kwatts = 209 HP ....
unless the evaporator is tired or needs a tweak ???
Systems only been in since 30/1/09 and done 12k in that time.
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As far as I know .. the sequent 56 will handle up to 30 kwatts /cylinder with standard injectors - page 32
http://www.remixbg.com/Documentation/Documents/Gazovi%20uredbi/BRC/SEQUENT%20Plug%20&%20Drive/Manuale_Seq_Instal_1_3_en.pdf
now 30 kwatts / cylinder x 6 = 180 kwatts which is 240 HP ... quite a bit more than an Omega 3.2 !!!
so the system "should" handle it ... but I suppose it could have the smaller evaporator ... which would limit it to 26 kwatts/cylinder .. but that is still 26x6 = 156 kwatts = 209 HP ....
unless the evaporator is tired or needs a tweak ???
Systems only been in since 30/1/09 and done 12k in that time.
I'm no expert.. so just trying to give any info I can ... I have the sequent 56 on my 3.2 and it handles the power without ever switching to petrol .. even when red lining it. The PDF link is about the best "description" of all the components in the system I have.
About all I can think of to do .. would be to check the type/size of vapouriser, type/size of injectors and compare to the tables in that link. If they all match the higher power requirements then the "design" of your system is good .. and its just a matter of finding out which "bit" is not working properly.
Obviously, if the bits don't match then that might be the problem !!! :)
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You really need to get the mapping software for the LPG system and see what's going on.
Firstly, a recalibration now the petrol ECU has adapted to the new cams.
If the LPG injectors are running out of duration and going fully on they might need the nozzles drilling out a little larger, assuming they are of a type that allows it.
If the vapour pressure is falling and prompting the switchover it points to something upstream, so vapouriser not able to deliver enough fuel, either by design or because, perhaps, the fuel line (6mm or 8mm?) or multivalve are now too restrictive for the fuel demand of the engine.
An acceptable solution, if something simple won't cure it, might be to set it to switch back to petrol at high RPM.
Kevin
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.. and don't forget the heating of the vapouriser itself. The hotter it runs the more vapour it can deliver, so ensure it has good coolant flow.
Kefvin