Hi guys, I started my car yesterday morning and noticed that it has now begun to idle and drive very rough. The exhaust sounds like it is sputtering/coughing and it shakes more than normal when I put my foot down on the accelerator. I was told by 3 other people that this may be a spark issue. Started the ignition, pulled off each spark plug lead one by one and noticed there is no spark coming from the third plug. Changed the plug and lead, yet made no difference. Does anyone have ideas of what may be the issue?
Edit: Car was converted to dual fuel in 2011, starts on petrol then switches over to LPG.
