Hiya people,

I'm new to land rovers and have just bought a T reg disco 1, 3.9 v8 converted to LPG. Only reason I bought it was because it was cheap and needed a couple things doing to it, plus it's a V8.

First off, when running on LPG if I accelerate too hard or there's an incline such as going up a slip road the engine will back fire through inlet. Yesterday I was towing a 9x5 trailer, up quite an incline and it backfired setting the bonnet insulation alight and was smouldering. I have read so many backfire threads and think I need to change plugs,leads,rotor arm and cap.

However, I was running on petrol on way home from work and after about 15mins of running it started to pop underneath the car and kept bogging down, no power etc.. Can a worn camshaft be the cause of both these problems??

One last thing, when cruising at about 50mph, it can start to sort of chug as if its struggling or misfiring and I really have to stand on accelerator for it to move, yet if I do this too hard it back fires???

Help please, I gather i need to plough a bit of money into her but would like to know where and when so to speak.

Cheers
Gaz

lpg does need very good ignition system ,and a poor spark will show up on lpg before petrol ,id start there ,also check inlet manifiold to head bolts

So your saying to change plugs, leads, rotor arm and cap??

when i had my LPG conversion done way back when, i know they changed the timing slightly to suit the LPG better. not sure whether its retarded or advanced, but i think it possibly does run better with the adjustment.
maybe someone else can advise better, but maybe it would help to check the timing too?

Right I've replaced plugs, ran great all be it for an hour and started running rough again and backfiring through inlet, yesterday i bought new leads from LR, fitted them but leads 7 & 8 don't bloody reach (any ideas?) will be ringing them this morning. And also ordering new cap and rotor arm.

On the way to work today had to run it on petrol, had erratic idling at junctions and when stopped, and popping underneath the car again, close to the cats would blocked cats cause this type of behaviour?

Can you explain how to check timing please

Starting to get really f***ed off with it now. These V8s ain't half a handful!

Gaz

do you have a second car you can use temporarily?
problems like this can often take a thorough approach, to have chance at fixing this yourself- which i assume is how you want to proceed, rather than dropping it at a garage (with a big bill at the end).
i am no way an expert here, but it seems to me that you may have to go through quite a few checks to find the fault through the process of elimination. thats how i work in my diy kind of way.
clean and replace all ignition system, check fuel pressure, have timing checked with e "timing gun".
i had a recent starting problem, and in the process went through all the wiring to double check things. i found quite a bit of damaged wiring, especially to the ignition amp. it seems it wasn't actually my problem, but was definitely worth repairing in the process.
if you put a multimeter between the + & - on the coil too and see what output you are getting.
when i checked mine it was putting out about 180v (bosch coil)
i would also consider cleaning (or replacing) the coolant temperature sensor. this can give false readings to the ecu and cause overfueling.

sorry there is nothing definitive, but its something to get started with.

some pictures on my recent thread maybe some help??

http://www.landyzone.co.uk/lz/f10/no-fuel-bad-relay-but-pump-can-made-run-228265-3.html

Thanks for the replies, spoke to LR and going to investigate the ht lead problem tomorrow, aswell as pick up a new dizzy cap and rotor arm! Will see how it runs after I've changed these!

What do I need to look out for when changing the rotor arm? Read something about holding something else down while removing it? Can anyone shed abit more light

Check ignition timing, check vac advance is working properly and check mechanical advance is working (see if you can rock the rotor arm back and fore). Remember ignition timing has probably been altered to account for LPG.

Only fit genuine ignition parts, pattern ones just don't seem to last very long or work as well as genuine which are expensive but oh so worth the extra cost.