Is it the 33"s, the LPG or because its been stood?

[muddymud]

well im very happy today i have got my first Landrover on the road  :lol: 1987 range rover classic 3.5 EFI V8 + LPG. :lol:

BUT

I purchased my range rover around a 10 months ago (with LPG) 1 months T&T left 100% standard apart from a set of 205/16 mud terrains. On the test drive it started and ran fine on petral, then when flicked to LPG it was running fine as well for about 1/4 of a mile then it ran out of LPG. (we did not pull up to a stop with it running on lpg)


Over the past few months i have got all the bits sorted for the MOT, Fitted a 2" procomp lift and 33" (255/85/16) BFG's. every so often i would start the truck for 15 muinets or so but its mainly just been sitting.


Today it passed its MOT, so i  took it out for its first real run since i got hold of it. At first i only ran it on petrol and found it a bit sluggish and it felt like you where pulling away in 2nd gear. Im guessing this is because of the Big tyres? No real problem.

A few miles in when the truck was up to temperature there was a strong smell of electrical burning! immediately i pulled over and switched the car off. I checked under the bonnet, nothing? i couldn't find where the burning was coming from there was no obvious burnt out wires and couldn't pinpoint where the smell was coming from. i started the truck back up and it was fine no problem, no smoke, no smell.

I filled the truck up with 40L of LPG, on the way out of the garage at around 30mph i switched over to LPG, there was nothing for a few seconds then it kicked in. as soon as it was running on LPG i noticed a substantial lack in power (it felt like i was back in my 1.1 fiesta) i also found when you pull up to a stop or put the clutch in the engine RPM drops off down to  around 200-300 RPM for a second then stalls, even if you try to pick the revs up from under 500 RPM it  wont do it! it will just back fire and stall, it sounds like its back firing through the intake.
it will start back up on LPG with a little bit of throttle, then the tick over will settle at around 900rpm fine. all though it will struggle to pull away. 

i have had the strange burning again around  5 miles after the first indecent but still couldn't see or smell where it was coming from. since then i must have done around 30 miles and it has not happened again and i haven't found anything not working.

what do you think? i hope i haven't missed anything out and sorry for the poorly written story it may not make seance.

Cheers,
Nick

[Rossko]

First make sure it's a real LPG issue.
LPG will mercilessly highlight weaknesses in the ignition system that pass almost unnoticed on petrol, and the V8s ignition is weak from the factory.  Lead/cap/rotor/coil/plugs condition, pickup airgap, try closing the plug gaps a little smaller than book - from 0.8 to 0.7mm
Check the airflow flapper moves freely.

If thats all in order, your LPG may have a tired or broken part, or just need setting up properly with an exhaust analyser.  I'm assuming it's not a feedback system at that age (oxygen sensor in exhaust) - if it were I'd guess the sensor wire has fallen onto the manifold.

[jay2578]

i had the same problem for a while, then i noticed frosting on the lpg pre-warmer thingy. turned out to be an air-lock, so undone a hose and forced water in with a hosepipe, problem solved

[muddymud]

ok thanks for your advice i will look into getting new leads and plugs, then if i get further problems i will take it to an LPG garage as i dont like the idea of messing around with it. i think it may need setting up as well.

Cheers,
Nick

[tack43]

Might be worth giving the LPG system a service.  ;)

Rich

[squaddie_fox]

give the LPG system a service, check and replace tired ignition parts. a good set of HT leads, spark plugs (cant remember which ones off the top of my head), genuine dizzy cap and rotor arm, and find yourself a bosch coil. the LPG system prefers the bosch.

check the airflow meter, maybe try a working one from another 3.5.

make sure you have no splits in any of the intake pipes and change the airfilter unless it has just been done.

[Range Rover Blues]

I've had a simliar problem, turned out the vacuum advance had pershed.

[muddymud]

ok so HT leads, genuine dizzy cap and rotor arm and a bosch coil. i have just fitted some NGK spark plugs tho.

i think that should do it. over the past few days the truck has been getting better and better, it is a lot faster with both LPG and Petrol. only problems i have with LPG is. It ticks over at 1500rpm which i don't mind. Also when your driving along on LPG with plenty of power then it will just loose loads of power and struggle to get up a slight hill unless you give it some? any ideas?

Cheers for the advice  :D

[squaddie_fox]

as said up there, check the vac advance as this may cause the lack of power.

[craig_midz]

get ya timing checked cuz when u gas convert ya car u have to alter the timing to get as happy medium as poss so u will never get em to run perfectly on both fuels unless u mega squirt it  but most ppl get the timing done so it runs perfectly on gas an lumpy on petrol have u tried ya ignition module found on side of dizzy when mine was playin up made my car loose power an made it hard to start an for a fiver part it was a cheap fix an made a hell of a difference