DISCO 2 MISSFIRE AGAIN

[martyn]

HI
I HAVE BEEN ON THIS FORUM WITH REFF TO MY DISCO2 4 LITRE V8 LPG MANUAL MISSFIRE PREVIOUSLY
 I HAVE CHANGED THE PLUGS TO RC11PYPB4 GAPPED TO 28THOU/ 0.07MM LAST OWNER HAD SOME UNKNOWN RUBBISH FITTED.
 IT HAS A NEW AIRFLOW METRE FITTED, K/N A/FILTER WHICH CURED THE PROBLEM. THANKS RANGE ROVER BLUES

BUT

ALL HAS BEEN GOOD  FOR 500 /600 MILES OR SO PULLING LIKE A TRAIN IN BOTH LPG + PETROL UNTIL I FILLED UP ON GAS THIS AFTERNOON IT HAD APPROX 10 LITRES OF GAS STILL IN THE TANK WHEN I FILLED UP DONT KNOW IF THAT IS RELAVANT BUT SHORTLY AFTER IT WOULD NOT PULL IN LPG IF I LET IT COAST OR V/LITTLE THROTTLE IT IS OKISH BUT NO SOON AS I PUT MY FOOT DOWN I HAVE TO KEEP CHANGE DOWN OR IT WILL STALL IT HAS ALSO BACK FIRED ONCE IT SEEMS AS IF IT IS EITHER STARVING OF GAS OR THE ENGINE IS BEING FLOODED WITH GAS CAN THAT HAPPEN?  
THIS LUMP OF SXXXX HAS SO FAR COST ME AN ARM AND A LEG, NEW FRONT EXHAUST ALSO MIDDLE ALONG WITH THE A/FLOW METRE + SERVICE £1600 + INSIDENTALS APPROX £250
MY OLD RANGE 3.5 PETOL 1982 NEVER LET ME DOWN AND IT WAS SOMEWHAT ABUSED BUT WITH THIS THING IT IS ONE THING AFTER ANOTHER THE ONLY THING I CAN THINK IT IS I NEVER POLISHED THE R/ROVER JUST POWER WASHED THE MUD OF BUT I HAVE WASHED + POLISHED THIS THING COULD THAT BE IT.
MARTYN

[remmy7]

Hi Martyn,

I too run a disco 2 on lpg and have had a missfire on and off pretty much since I got it and it has also cost me an arm and a leg to run on the engine side alone it has had the following
air flow meters x 4
ignition leads
new coils
full top end overhaul with decoke and skimmed heads
new camshaft
new valves
piston rings
crank sensor
camshaft sensor
knock sensor
The list is not complete but it gives you an idea of how often its been to the garage. Each time it comes back it runs ok then after a few hundred miles it starts to lose power and very quickly develops a missfire. Whilst it has never been mentioned at any time I am now thinking that the engine management may have something to do with it as it has been reset every trip to the garage. Could it be that it just cant cope and after a while gets itself so bogged down with all the sensor data that it loses the plot. I am no expert on these things (in fact i know nothing about them) so I may be completely wrong but it would be interesting to hear if there are any other disco 2 v8 owners with similiar problems. By the way if I let the problem with the missfire on lpg go on it soon develops on the petrol as well. Please let me know how you get on because my vehicle is just out of the garage and is starting to deterioate again already.

Regards Remmy7

[martyn]

Hii remmy7
Sorry to hear about your Disco troubles i dont think i could be patient as you have been
 This car had a new block piston etc just before i bought it along with new clutch.
It has had the management system cleared and remapped for 2007.
Anyway this aftrenoon i tried it out in gas and it works perfectly as if nothing   is wrong, so i give it a good thrashing over the mountain road frigtened a few cars also took it of road so it can appreciate that it has had an easy life so far nothing serious but i have left the mud on it this time just to teach it a lesson.
Makes me wonder about he management system tho.
 When it did play up yesterday it did start to miss ocassionally then just run bad.
Good luck with yours.
Martyn