Bedford ignition issues! Help!

Hi there,
Bought a 58 bedford D acouple of months ago, just got it converted to dual fuel which ran real good on petrol and gas for 200 kms then started to misfire on both petrol and gas, so not sure if it is a result of converting to gas or not.
Any how, I took it to my mechanic this morning who mucked round with the distributor (changing the gap, clean the points etc) he got a good spark going from the dizzy however the engines misfiring was now much worse, I went down the road and changed plugs and leads, it still ran rough, took it back to my mechanic, more fiddling round with the firing order and checking leads etc, he decided there was not enough output from the coil and not enough spark getting to the plugs. So I went to drive down the road to get a new ignition coil but 100 m down the road the truck started to run really rough, felt like only one cylinder was working by this point. I got another car changed the coil over - it wouldn't fire, went back and got another coil and got it to turn over but still really bad misfiring going on. So I don't know what else it could be, mechanic said the condensor was fine, I've changed plugs and leads and now a new coil, cleaned points and rotor but now it won't even run?????!!!??
Help much appreciated!
Steve

Steve, Try another condenser first, as you have been changing plug leads guess you had a look at the cap for cracks and a clean inside and out.
Make sure you have the right coil, some work with a resistor others don't. Cheers David.

Sometimes running a wire directly from battery to coil earth makes a difference.

Bedfords had a habit of doing what you say.
Check for too much slop in the distributor shaft.
If there is any slop in the shaft,tighten the distributor locking bolt down a bit more,this will take out any slop from a buggered bearing shaft.
Sounds a bit rough but it works until you replace the dizzie bush.
Worked for me over 4 Beddie motors over the years.

If all else checks out then check that the gear on the dizzy drive shaft has not let go, I have seen the securing pin disappear. Another one I had with similar symptons was in a reco engine where the woodruff key for the camshaft gear had been left out. This let the gear move on the camshaft eventually stopping the engine.

Steve, try a look at the wiring at the back of the ignition switch, I have had them simply rattle loose/ fall apart from the years of vibration.
Cheers
Alistair

Assuming the ignition is all sorted, Does it crank over normally; i.e.: with even compression. The LPG may have "cleaned up" the valves and seats; a quick valve adjustment may be all it needs. It may start cold and then conk out when it warms up.

Thanks for the replies guys.
The rotor on the dizzy was a bit loose, which was the next thing I was going to replace, I just didn't think that a loose rotor could cause the engine to not fire. Sounds like the components in my distributor may have seen their day. Maybe I should just replace the distributor.
One other thing I did notice was the that comes out of the distributor (the one on that wierd clip) and goes to the negative terminal of the coil has some exposed copper, looks a bit frail but isn't shorting or anything... Hmmm

Asw, I've been running it soley on petrol the last couple of days, I switched it over to lpg once today in desperation but it had the same symptoms- barely running, when I changed it back onto petrol it refused to even fire, even after I put the new coil in. I learned today that my bedford runs a coil that needs a resistor, I did two stops to repco today

Good to hear you found it. I've never had a rotor that loose on the shaft, one for the memory banks. Not much holds them on. (I've had the button burn up in the cap and the coil lead do the same, but not what you had)

I've had valves close up before, hence the suggestion.

Have fun with it.
ASW.