hi i have a 4L 1999 cherokee orvis n is rubbish on fuel i am running it on lpg gas n i put 20quid in which is around 37 lites of fuel n it will do 70 miles averge, it seems to shift late to n feels over reving around 2500 rpm at 80mph, it also idles bit lumpy n has around 2000 rpm pulling away the engine judders, please help

 

Hello Jonny, welcome to the forum from Fantic.
I would do 75 miles average with 37 litres of LPG on my ckee, it is quite normal for the 4.0 engine.
What you probably have is a bad regulation of the propane reducer, i could really help you more if you post some pics of the reducer, diffuser or lpg injectors, and the lpg hose that goes from the reducer to the intake.
Are you in GB? then you probably have an Italian lpg kit like Romano, Brc, Landi, Lovato or Stargas.
We are authorized installators for BRC, Romano and Stargas, and unauthorized for all others.

 

yeah wen i 1st bought it i drove back from wales hereford to ringwood onm 20 quid and i did 120 ish and that is good
but now im halfing that and if i put 20pounds of fuel in i get around 70 miles so that means is doing av 16 mpg on fuel n 8 on gas

 

That is normal, when you drive on the highway you get much better mileage, post up some pics and i'll tell you what to do to get a better fuel economy, but i need to know what kind of kit you have.

 

so its normal to be doing 8 mpg on lpg and out the factory they do 19 and on petrol doin 17 18

 

On Lpg normally you get from 2/3 to 1/2 mpg of the petrol mpg (yes, less), but the lpg cost per gallon is 1/2 or less the cost of petrol, so there is the advantage of using it.

 

so your saying that there is an advantage in paying half price for the gas and only getting half the milage? i dont get it?

 

I said from 2\3 to half, depends on the regulations.