Lpg Conversion

February 6, 2008

Hi to everyone, new to the forum so this is my first post, within the next few months i've decided to trade my old espace for a petrol auto previa 96 on, due to the extortionate rise in petrol costs i am considering an lpg conversion and have a few questions that you may be able to help with, firstly are these systems as good as they advertise, i have worked out on how much i would save on fuel costs which is very encouraging, but am looking in terms of reliability etc also would i benefit from fitting the latest type system with 4 injectors as opposed to the single point system as recommended, if anyone can offer advise from a users piont of view i would be very grateful, thanks in advance,

regards paul.

ps sorry for the swear word above..........

April 7, 2008

Hi to everyone, new to the forum so this is my first post, within the next few months i've decided to trade my old espace for a petrol auto previa 96 on, due to the extortionate rise in petrol costs i am considering an lpg conversion and have a few questions that you may be able to help with, firstly are these systems as good as they advertise, i have worked out on how much i would save on fuel costs which is very encouraging, but am looking in terms of reliability etc also would i benefit from fitting the latest type system with 4 injectors as opposed to the single point system as recommended, if anyone can offer advise from a users piont of view i would be very grateful, thanks in advance,
regards paul.
ps sorry for the swear word above..........

Hi Paul

Apologies for the tardy reply - I've been away for the forum for some time (no problems with the ol' bus y'see...)

I've had my 2.4 GL Previa for nearly 5 years now... Bought it with an existing Landi-Renzo LPG conversion. (or so I thought)

Turned out that the L-R vapouriser had failed and been replaced (by persons unknown) with an OMVL R90 unit... Also turned out that the 40 litre toroidal LPG tank (quoted on the LPG cert for the vehicle) had magically relocated to the boot space and become a 110 litre cylinder..!! :o

So... If you're buying a car complete with LPG conversion, check the paperwork against the vehicle... Just to be sure...

If you're paying to have your own vehicle converted, a multi-point injection system is the state of the art (at the moment). You'll be blinded with science as convertors talk about different "front ends" and "rear ends" and how the two interact, but the most telling evidence of a convertor who knows his stuff is from folk who have already had their conversion done...

Anyway... you wanted to know how it works from a user's point of view...

Our system was quite problematic at first... The car runs an OMVL R90 with single mixer... We bought the car at 120K miles and it had been converted at 80K. The car wouldn't idle on LPG and often stalled on the overrun... I stripped out the LPG mixer and petrol Throttle Body... They were both coated in slimey mank... The Previa engine breather feeds into the inlet duct (just before the LPG mixer on my car) and coats everything with this gunk... The Haynes recommends removing the TB every 60k and thoroughly cleaning it... I did just that, cleaned out the mixer too and the improvement was like changing the engine..!!

We live North of Glasgow... Sometimes it gets VERY cold... The LPG system is supposed to have a temperature sensor that only allows fuel switchover when the vapouriser has reached working temperature... Whoever removed the L-R unit from our car, didn't bother trying to refit this sensor to the OMVL unit (not sure it would fit anyway) So there is no temperature input and the car will TRY to run LPG whenever the gas is switched on and the revs pass 2k rpm... If it's too cold, the engine cuts immediately... Can be troublesome if you passed 2k rpm when pulling out of a T-junction..!! :o

Also - a couple of winters ago, we had problems after the snow had started to thaw... The local roads were literally running with deep ice-cold water... If the car was driven through a particularly deep section of this water, the vapouriser would be suddenly reduced in temperature and allow almost completely unvapourised LPG into the inlet tract... This would move toward the hot engine, rapidly expand in the tract and blow the coupling off the back of the air mass dectector... Result, 1 dual-fuel Previa, that won't run on either fuel..!

We're wise to these situations now and know when to avoid using the LPG... Extreme cold has been the only real problem... Availability of LPG isn't a problem and we see prices varying between 67p/lt (closest, of course) to 47p/lt (furthest away...) Most of the time we're paying 50p/lt at Asda or Morrisons and we've picked up an Asda credit card to buy fuel with as it gives an extra 2p/lt off when we buy fuel... :D

This reply is so late you may well have stumped up for your kit... If you have, what type did you go for..? How much was it fitted..? and how are you finding it in use..? If not, hope this helps...

BTW: Our bus is H Reg and passed 200k miles last month (Hurrah for her..!! :lol: )