LPG on a Chevvy

Discussion in 'All the Rest' started by nahnotme, Jun 4, 2009.

  1. nahnotme

    nahnotme Read Only Funster

    Joined:
    Sep 23, 2007
    Messages:
    239
    Likes Received:
    0
    I purchased a Winnebago Itasca a few months ago and was told that it was running lumpy on LPG so needed servicing. Having had the petrol side of the engine serviced, plugs, leads, distributer cap all renewed, I was told by an LPG specialist that the exhaust manifold gaskets were blowing and have been quoted about £400 by my usual garage to replace them although 2 of the mechanics say they arn't blowing and 1 says they are slightly and I cant tell as im deaf and dont know what im looking for.
    The LPG is a LO-GAS single point system with lambda feedback and has had two air filters changed.
    I only do 100 miles a week but am planning on touring spain for the winter, though I know PLG service stations are a rarety there, so dont want to spand much money if its not going to be re-couped.
    So I suppose i'm asking if any one has any similar experiences or can offer advice as to what I should do, bearing in mind I have VERY little money.
     
  2. johng

    johng Read Only Funster

    Joined:
    Aug 15, 2007
    Messages:
    588
    Likes Received:
    0
    Location:
    Kent/Sussex UK
    hi Wynnie

    I also have a chevy and it's lpg'd, and exhaust leaks, and i have little money :BigGrin:

    will have a think about the rest, or someone else wil come along nicely with an answer
    John


    ps where are you? edit.. Lancashire.. miles away from me.

    pps on a cold engine, you can 'feel' for the leaks, watch those plugs leads and also the exhausts get damn hot, quick.. if there's a noticeable leak from either manifold you should feel it, as long as you can get your hands around all sides of them. (may need to pop underneath with a torch and have a feel..)
     
    Last edited: Jun 4, 2009
  3. juliandavies

    juliandavies Read Only Funster

    Joined:
    Dec 12, 2008
    Messages:
    73
    Likes Received:
    0
    Location:
    Crystal Palace, London
    I've got a petrol Chevy and it clearly had the same problem before I bought it.
    It has been bodged with a Hermalite seal around the manifold which I am assured will be fine...unless its cold!
    Should probably get it fixed!
     
  4. johng

    johng Read Only Funster

    Joined:
    Aug 15, 2007
    Messages:
    588
    Likes Received:
    0
    Location:
    Kent/Sussex UK
    what engine is it Julian ?
     
  5. Geo

    Geo Trader - Funster

    Joined:
    Jul 29, 2007
    Messages:
    9,546
    Likes Received:
    5,596
    Location:
    Mansfield,Notts
    If memory serves I was told this is a very common fault,and a devil of a job to do:Eek!:
     
  6. johng

    johng Read Only Funster

    Joined:
    Aug 15, 2007
    Messages:
    588
    Likes Received:
    0
    Location:
    Kent/Sussex UK
    one of my manifolds is cracked :cry: havent had the nerve to take it off.. also , all bolts are very rusty.. leaving mine be for now
     
  7. Geo

    Geo Trader - Funster

    Joined:
    Jul 29, 2007
    Messages:
    9,546
    Likes Received:
    5,596
    Location:
    Mansfield,Notts
    A very wise move
    its definatly a wait till you must jobby
    cylider heads off if you snap them thar bolts:Eeek:
     
  8. juliandavies

    juliandavies Read Only Funster

    Joined:
    Dec 12, 2008
    Messages:
    73
    Likes Received:
    0
    Location:
    Crystal Palace, London
    chevy 454 CID-7.4 liter v-8 ef injected engine
     
  9. Sundowners

    Sundowners Funster Life Member

    Joined:
    Oct 30, 2007
    Messages:
    2,346
    Likes Received:
    1,404
    Location:
    Suffolk
    We had a V8 Land Rover "gassed", it was never properly set up and used to "run a bit strange" BUT it kept going and was VERY cheap to run.
    So, in your position, if it runs OK and is not burning too much gas, I would drive it and enjoy a "cheap to run " motorhome, in the meantime, try to get more info on the manifold gasket.
    I don't know, but would have thought it would have the same problem running on petrol ??????
    GEO would know but, wouldn't it fail MOT with ex. manifold leaking ??????????????? Also they used to MOT on the fuel it is driven into the MOT station on???? (our Landy would never pass on gas!!! so I used to switch over to petrol once a year)
    Enjoy your m/home
    Nigel & Pamala
     
  10. johng

    johng Read Only Funster

    Joined:
    Aug 15, 2007
    Messages:
    588
    Likes Received:
    0
    Location:
    Kent/Sussex UK
    I have a feeling Nigel it's got to be excessively leaking.. a nice mot'r might leave be :)
     
  11. Boo

    Boo Read Only Funster

    Joined:
    Jan 26, 2009
    Messages:
    636
    Likes Received:
    4
    Location:
    Cornwall
    The same as the one I had in my C class...........that was gassed too and ran lumpy.

    I ended up paying £300 for manifold gaskets fitting (broken bolts were drilled in situe) a new diaphram for the gas and a gas setup costing £150, ran beautifully after that all round portugal..............it was money well spent :BigGrin:

    Boo
     
  12. American Dream

    American Dream Read Only Funster

    Joined:
    Aug 20, 2007
    Messages:
    6,489
    Likes Received:
    154
    Location:
    Lincoln
    There is a product on ebay that is made for the job and would fix this leak.

    ABRO Thermometal...Good stuff but not cheap.You get what you pay for.Just make sure the manifold is ground out around the crack to provide a good key.Would certainly last until you can change the manifold.:thumb:

    You dont want those hot gases causing other problems nearby.
     
  13. nahnotme

    nahnotme Read Only Funster

    Joined:
    Sep 23, 2007
    Messages:
    239
    Likes Received:
    0
    Running on LPG isnt just lumpy its it isnt running !!
    first few times I tried it it would go 10 + miles then the engine would pack in. I then had the two small air filters changed and on a test drive it lasted about a mile, the last time I tied it the engine cut out immediately. If it was just running lumpy I would risk it but when my engine stops so does the steering etc. which is dangerous on the open road.
     
  14. olley

    olley Funster

    Joined:
    Jul 29, 2007
    Messages:
    3,719
    Likes Received:
    2,121
    Location:
    Ipswich
    Hi winnie you don't loose the steering, just the power assistance, which means you have to have arms like a gorilla to turn the wheel. :BigGrin:

    It sounds as if you have a gas carb, if so it works on manifold depression so would I think be unaffected by any exhaust leaks. The first thing I would check is the vapouriser, thats about 6" round made of ali, with two gas and two water hoses going into it, its usually mounted close to the engine.

    Start the engine and when its warmed up see if the water pipes to the vapouriser are getting hot, it must have hot water going to it for it to work properly, otherwise it would work for a while before freezing up.

    It will look something like the one below.

    Olley

    [​IMG]
     
    Last edited: Jun 5, 2009
  15. lebesset

    lebesset Read Only Funster

    Joined:
    May 31, 2009
    Messages:
    760
    Likes Received:
    1
    apart from the costa del sol you can get around spain on lpg presuming you have a reasonable tank capacity ...the pay back time on repairs will be short ! can't imagine what it will cost you to get across france using petrol

    Spainautogas

    last winter I think all the sites listed except the one in central zaragoza were available

    repairing the manifolds and getting the gas system sorted out should be an excellent investment ...despite my 25 years running on lpg I can't recommend anyone in your part of the world ....southerner myself ....personally I would phone gordon finlay [ see website ] near exeter as he is vastly experience and a practical rather than theoretical sort of guy ....expert on V8's ...well worth a visit if he says he can handle it [ en route to france /spain? ]
    Gordon Finlay LPG Conversions, index. We give your engine muscles on LPG.
     
  16. nahnotme

    nahnotme Read Only Funster

    Joined:
    Sep 23, 2007
    Messages:
    239
    Likes Received:
    0
    yeah ive got 2 of them, do I get it warm on petrol or try with gas ? cos I dont think it will get that far ???
     
  17. Pete45

    Pete45 Read Only Funster

    Joined:
    Jan 29, 2009
    Messages:
    191
    Likes Received:
    72
    Location:
    Milton Keynes Bucks
    Hi, Get it warm up on petrol,then over to gas.Then see if it is getting hot.if not see why not. Pete (Arizona Chief ):thumb:
     
  18. nahnotme

    nahnotme Read Only Funster

    Joined:
    Sep 23, 2007
    Messages:
    239
    Likes Received:
    0
    The vaporiser pipes are getting hot but as soon as you flick it over to LPG the engine cuts out. soooooo.......I think im going to get the blowing manifolds re gasketed and see if that makes a difference, knowing my luck it'll be a few hundred quid down the drain. Though Im told it should be done to avoid future more major problems.
    OLLEY Im told it is a gas carburetted system but I dont know what to believe or who to do work on it.
    My local commercial garage says they'll do the gasket but cant see it affecting the LPG system. One LPG specialist in liverpool changed two air filters and said they couldnt sort the problem as it was multipoint system and they didnt have the software, it has since got worse !
    Pioneer LPG fitters in Rochdale said that software isnt needed as it is a single point system with lambda feedback, what ever that is, they suggested first thing to do is change the electrical brain box at £350 so that it can be diagnosed by computer....
     
  19. johng

    johng Read Only Funster

    Joined:
    Aug 15, 2007
    Messages:
    588
    Likes Received:
    0
    Location:
    Kent/Sussex UK
    hi Wynnie

    Lamda feedback means

    A lambda sensor in exhaust tells the lpg system how things are , down in the exhaust pipe.. it measures the fuel/air ratio using emissions..

    if you have exhaust leaks, then there may be excess oxygen going towards the lambda, from the leaks, upsetting running of the lpg.. I wouldn't expect it to not run at all, mind

    JOhn
     
  20. olley

    olley Funster

    Joined:
    Jul 29, 2007
    Messages:
    3,719
    Likes Received:
    2,121
    Location:
    Ipswich
    Hi Winnie, their are two types of LPG conversions, the oldest is the gas carb, and works solely on manifold depression, no electrics apart from an off/on switch, the more modern version of this had Lamba control to alter the mixture, the second and most modern is the multipoint, this has much more sophisticated electronics.

    The Lamba sensor measures the amount of oxygen in the exhaust gases, and the ECU uses this to adjust the mixture. You can check the sensor by using a multimeter, but if it runs ok on petrol I think its probably ok. Here's an explanation: Lambda sensors / exhaust oxygen sensors

    You should have a relay somewhere that's operated by the LPG on/off switch, mine failed a couple of years ago, and it would only run on Petrol till I replaced it, cost a fiver I think.

    If yours is the gas carb with Lamba sensor then it could be the stepper motor in the carb that's u/s, just a thought; you said you have two vapourisers? do you have two carbs then??

    Personally I think you need to take it to an LPG specialist, rather than a stab in the dark spending £200 replacing the exhaust gaskets.

    Olley
     
Loading...

Share This Page