Strange Coughing Problems, Advice Needed Urgently

[ReubenGB]

When hot this earth contact could break down giving trouble on whichever fuel you're running on at the time. Breaking down at the roadside for a while (cooling the connection), then switching fuels and all's ok could possibly be a red herring.

The most recent occurrence after the mechanic gave the all clear we didn't actually break down, switching from LPG (in which it was failing) to petrol mid-drive cleared up the problem; it had been losing revs and coughing, seemed about to die but picked up immediately in petrol and drove without problem...so would the earth contact still be a possibility in this scenario or not?

[ajsimmo]

Ok, in that case it sounds unlikely to be the common earth theory. The dual fuelling theory fits the described scenario much better.

[itchyfeet]

Easy to test
Your lpg should have four switch states, on mine these are indicated by lights (in brackets)
lpg ( green or yellow)
petrol (red)
lpg and petrol ( greenor yellow and red)
nothing ( no lights)

As far as I know the LPG indicator had only two states on our conversion, in LPG it shoes green&yellow lights, in petrol a single red light. I have never seen it with no lights or both at the same time...

when you switch a carbed engine from petrol to gas you still have petrol to use in the carb float chamber up hence the no fuel state
when you switch from gas to petrol that float chamber takes a few seconds to fill hence the both fuels state.

how did your installer tell you to switch over?

[marlinowner]

If its running OK on petrol at the moment I would shut the valve on the LPG tank so there is no possibility of LPG reaching engine, manually open or bypass the petrol cut off valve and run on petrol for an extended period to see if it behaves itself. If it does then take it to an LPG specialist when back in UK.

[ghost123uk]

That ^^^ makes sense.

[ReubenGB]

Hi All!

Thanks for all the advice, and sorry for the late update to the thread, but I haven't have a decent wifi connection in more than a week...because we've been travelling!!

We took the van to Karvans, a great T25 place near Seville, and it's been running perfectly ever since.

They changed the spark plugs just to be sure but said they looked ok, they also took out a petrol filter which had been put in when they did the LPG conversion; it seems they didn't realise there is already a petrol filter under the van and put another in between the fuel pump and the motor, sitting on top of the engine. This was causing problems as there was air leaking in, pushing the fuel in the filter back to the tank and leaving the filter empty...there was some explanation as to why this would cause us to stop on gas but I don't remember exactly/didn't understand completely (it was in spanish...!). Anyway, we've made it all the way to Bordeaux, France and we're heading up to england, without a glitch so far!

Thanks again to all for your advice and help!

[ghost123uk]

Glad you are sorted

Though the bit about the 2nd fuel filter issue causing it not to run on LPG is not right, that might have been plugs, or summat they found but did not make clear.