backfiering

[edy]

hi, the rangie 3.9 is backfiering, lots, it is running on LPG. wondering doese anyone know what it is, it went ok for a while but seams quite bad now, its doing it a lot. could it be plugs maby??? i was told it could be the vaporiser, you need coolant to stop it freezing up, the level says it is full but when i feel the top hose it feels like there is nowt in there. it could be this, would explain why it is having trouble (with it being cold). was also told it could be somthing to do with the 3am (hope not they dont seam cheap).

any sugestions appriciated.

[scooby]

i  have just had my one converted and i did ask this to the man who instaled the gas on my disco as my mates get backfire and he said 99% of the time its down to the ign side of the car which is rotor arm dis cap plugs and leads. the gas should run fine in the winter and summer but most of its down the the elec side of the truck. my mate has done his now and runs fine.

[landraver]

Hi Edy, Like Scooby said, it could be your ignition timing so to test this get a permenent marker and mark where your distributer meets the casing (so you know where to put it back to if that isn't the problem), loosen the bolts & see if things improve when you move it left or right. It's a starting point anyway :D

Jeff

[edy]

ok, cheers, will mess about with the timing, cheers :D

[Range Rover Blues]

Your plugs need to be closed up to 27 thou.

Your leads need to be in very good condition, as does your coil.

LPG is harder to ignite, it has an octane rating of 115, so quite franlky the timing becomes irrelevent, it will still run with timing that would cause petrol to pre-ingnite like a deisel.  Moreover the timing will be retareded for LPG to get it to start on petrol, the more you advance it the harder it will be to fire up in the morning.

When Blue backfires a lot it's usually because it's burned a valve out :shock:  but other causes are lean mix (running out of LPG for example) and weak spark or incorrect plugs.

[dod51e]

When the P38 started backfiring I took it to the chaps that fitted the LPG.  They did their tests and pinpointed ignition leads.  All was fine on petrol but as has been said, LPG takes a bit more igniting.  A new set of leads later and all was fine.  I would recommend genuine articles as saving a few quid on leads realy is a false economy especially when running on gas.
Hope this helps.

[Bowie]

Oh, a full set of genuine leads is only around £26, so not really out of this world :)

If people need a link to buy them, rather than get them from a LR dealer, lemme know ;)

[edy]

cheers for the posts :)