Thor V8 Misfire

[Jon W]

I am opening this to the board as more views in here hopefully.

I have a discovery 2 with 4.0 V8 and lpg conversion.

Up until now it has run a dream and no problems at all.

However it failed to start the other week due to a failed starter motor. Recovery guys came out to my wife. Did the old hit the starter trick and sprayed some brake cleaner in the air intake to get it going as they said it was turning over slowly. 

On the drive back it all started to go wrong. With lack of power and misfiring and struggling to maintain speed. I dropped it at the garage on my way home as didn't have time to put a starter on it and needed them to do a few jobs for the MOT. 

2.5 weeks later,. they still havent got round to it so I have given up and taken the vehicle back. 

They have:

Changed the spark plugs - this improved things slightly

Said they put diagnostics on it and nothing is showing up as faulty, they checked MAF etc.

Fault is present whether on LPG or Petrol

So where shall I start? Coil Packs? It has magnecor leads already on it 

When cold if you touch the throttle it tries to flood and really struggles.

Any help appreciated,  I hoped the garage would put it on diagnostics and know where to look but they are hopeless and have to much work on to give it anytime. 

Thanks 

 

Jon

[Jon W]

Think I have tracked the problem down to a ignition lead arcing out. But could be more than 1 due to how badly it runs or possibly a coil pack on the way out. Shame it is so hard to reach the coil packs on a D2 just to swap some lead out.

A job for the weekend I think

Thanks 

 

Jon 

[elbekko]

I'd definitely look at ignition, yes. Take the plugs out and see which ones are firing?

[FridgeFreezer]

If it runs the same on petrol or LPG it's not fuelling related, that leaves ignition.

Coils, leads, crank sensor.