P38 4.0 range rover runs fine on petrol really bad on LPG

Runs perfectly on petrol, idles ok on LPG but any load and it is jerky and lumpy, and getting worse, am no expert on this so need tender care, thanks

Having the system serviced may help a little. Playing with LPG if you don't know what you are doing maybe harmful to your health.

Single or multipoint system?

GEMS or THOR engine?

Have the MAF or O2 sensors been played with recently?

Grrrrrr said:

Have the MAF or O2 sensors been played with recently?

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thanks everyone,

Thanks everyone, it is a gems, and havent played with anything yet, it is a Leonardo system, if that helps. Are there injectors i could check, if so where are they. single point, multipoint? I live in Wales near Brecon, so no service places nearby.

crawnon said:

Thanks everyone, it is a gems, and havent played with anything yet, it is a Leonardo system, if that helps. Are there injectors i could check, if so where are they. single point, multipoint? I live in Wales near Brecon, so no service places nearby.

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I know naff all about LPG but I'm sure I've heard rough running on LPG but OK on petrol on here before. Google is your friend there. Onthe end of your search you can add ":landyzone.co.uk" and it will restrict itself to this website. Although I think this forum might be on Google now anyway so the search probably works. Back of my mind was non-standard or dirty MAF or O2 sensors giving issues. One of the LPG gurus will know.

Not the same engine I know but
I had a 110 3.5 V8 on carbs with an old LPG system, if I didn't clean the in-line filter in the system on a regular basis say every 5k miles I would get the same problems as you describe.
Easy to wash out the gauze and filter bowl with meths and roberts your mothers brother, BUT the black residue that clogs up filters over time is IIRC called "heavy ends" and is highly carcinogenic. I always took very great care when doing this.

Run it on the proper fuel then

before getting to grips with investigation have the lpg filters been changed recently ?

crawnon said:

single point, multipoint? I live in Wales near Brecon, so no service places nearby.

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Multi-point, you should have secondary - extra - electrical plugs and injectors above each petrol injector. Single point, you'll probably have a single gas feed line going into the plenum. Had my single point ripped out and a multi-point system installed. Also worth checking all electrical joints where the LPG system is connected to the car. Soldering on mine was atrocious.