This vehicle had been to two other repairers.
One garage replaced spark plugs. the other could not fault it.

I was asked to have a look. First checked fault codes with IDS none stored, No pending codes either.

At idle every now and then engine would miss a beat, I connected the scope using the WPS in the exhaust pipe, and ignition on cylinder four. (As the inlet manifold covers cylinders 1,3 and 5).

Then waited for the engine to miss, this is what I captured


Seeing the misfire event from using the WPS I was able to identify which cylinder was at fault.

Suspecting the coil or faulty plug I decided to move the coil and plug from cylinder one to cylinder six which was accessible.

connected the scope again this time picked up primaries on cylinders four and six with the WPS connected waited again for engine to misfire and see if my calculations where right. This is what I captured



You can see that this proved and located the cylinder which had a misfire, New coil fixed the fault. and no unnecessary parts where fitted. with out the scope I would have been guessing like the other workshops...

Darren