Fiesta Misfire

[coxmattycox]

Hi all,

My 51 reg fiesta starting running rough tonight, engine stuttering. I've put it through my reader and it reads P0303 cylinder 3 misfire detected.

Am I right the first thing to check is the Coil pack/HT leads? Should they appear soiled or something if they are faulty?

Is there a way of fault finding to see which it is?

The only other thing that happened lately, is the car was full on Petrol, then parked on a slope and the petrol started leaking through the overflow? Not sure if this would cause any damage?

Thanks in advance

 

[squerble]

I had the coilpack & leads replaced on my Fiesta about two months ago. Is the stuttering happening at lower revs? I found that above ~2krpm I could barely feel it. It appeared mostly under load.

I changed the spark plugs first (the gaps on the old ones were all to ****), and was going to try disconnecting the MAF, but ended up taking it to a garage. Came back straight away with coil pack diagnosis so I got it changed. Absolutely no problem since.

 

[miniyazz]

Swap the cylinder 3 bits with the cylinder 2 bits and see if the misfire moves to cylinder 2. If so, move everything back bar the spark plugs and see what cylinder the misfire is on.