Another engine misfire problem DE

[TimC]

Hi, I think I am getting somewhere with sorting this but just asking for a little help on a number of things, firstly this is what's happened so far.

 

Taking the zed out for a day out but it started to go wrong with a single misfire and then it was ok for a further 10 miles. I stopped to check I was on the right road and with the engine idling it started to idle uneven with a popping from drivers exhaust and a slight smell of petrol. I thought time to turn round and go home, at higher revs it seemed ok but pulling up to traffic lights or junctions it started again. I never got a engine light come up and checked with code reader later and no errors showed. Next day I pulled out some old coil packs from an earlier swap, to check to see if they were ok, one measured faulty (infinity or high ohms) on a resistance check so I binned that one, others were ok and started to dismantle the car. Passenger side 1st coil pack swapped over ok, second one I pulled out and found corrosion on the inside of the coil pack and also on the top of the spark plug. Not good I thought so made a note to order some new plugs and a plug socket to pull it out. I carried on anyway replacing 2nd coil pack and 3rd coil pack. Only 2nd one had the corrosion.

Everything went back together ok and I thought I would start it anyway to see if there was any change. It was still not right but the popping had stopped and it was still misfiring and still smelt of petrol at the exhaust exit. I measured the coil packs I had pulled out and 2 measured faulty, 2 and 3, I was not expecting that. I assume I had been driving it with a faulty coil pack for a while or 2 had failed on the journey back, strange.

So from the picture above with all the corrosion, what could have caused it and will it happen again?

I assume the smell of petrol will be from the fact that there is a poor connection between the coil pack and the spark plug and it is not igniting the petrol in the engine? Replacement will prove that.

When I unplugged and plugged the coil packs in I got the 2 and 3 wires muddled as you have to pull the wiring harness back to get access. I assume they are wired the same on both sides of the engine, 1 and 2 come out of the front of the harness together and 3 from the back on its own. That's how I wired it up so right and left sides of engine were the same. Also I think it would have really throwed a major wobbler if 2 and 3 were the wrong way round.

I need to get a spark plug socket, I think its a 14mm, either of these two are what I need?

Laser 3/8"D Spark Plug Socket - 14mm Bi-Hex - Wilco Direct

MAGNETIC PLUG SOCKET - 14MM - 3/8D" | Halfords UK

 

That is were I am at the moment, hopefully someone can advise or may have had the same problem and fixed it. I have fingers crossed for a spark plug change fixing it

 

 

[TimC]

Well I got it all sorted, new spark plugs and 2 new coil packs and it works so much better when the coil packs are plugged in the correct way round. It seems that the coil pack plug which comes out of the middle of the loom is plugged into the back plug, not the way it looks. 

[ZMANALEX]

A very common error and easily done.