v8 LPG problems and only 8mpg

I've have my 3.9 v8 disco a week or so now, Iv noticed I'm filling up on 55L of gas with twin under tanks, I would of thought that £35 would of got me a few more than 119mile. The car also runs very lumpy on tick over and sometimes takes ages then turns off. I've also had enough a few experiences with a horrible has smell on change over.

Could any shed some light and let me know what's happening please thanks, this is all very new to me

Do you know if the oil has been changed frequently in the past? Otherwise the cam may be worn, I would check the compression too.

Saying that, your MPG is not that bad for a Disco V8, as LPG is a weaker fuel than petrol.

I'm not really sure, I know it had a service a year ago. I think the problems are a new thing though as it has been fine over the last year, it was bought from a friend so Iv know the car a while

Hi,

What you are getting seems about right to me. When I got my Disco it would do about 115 miles to 50 litres of LPG being driven normally.

The addition of a roof rack took this to 110 miles.

Having spent the last year going through the vehicle checking every single thing including fixing a leaking inlet manifold, new ignition components, setting up the LPG system correctly, new lpg filters, cleaning lpg injectors, checking the petrol injection components with rover gauge and replacing a faulty 02 sensor and some experimentation with ignition timing (it runs best at 18 degrees BTDC) I am now getting 150 miles to 50 litres of LPG!

So all that work has taken me from 10mpg to 13.6 mpg on lpg, and it run perfectly on both fuels and changes over nicely!


With regards to the smell I used to get than but new filters cured it.

Out of interest what is the LPG system? Make and model?

Kind regards

Neil