Hi Guys, new to the forum

Ford fiesta finesse 2004

62k miles

Bought this little car from a dealer about 8 months ago (first car!) and have thought myself incredibly lucky as I have had no problems with it... until now.

A few days ago I pulled up at the wrong pump that only did super unleaded rather than normal unleaded, and I couldn't be bothered to move the car so I just filled up with that, not thinking much of it.

I don't know if it's a coincidence, but ever since then my car has been occasionally misfiring when going 30mph+ with the engine light flashing intermittently. I got it checked out today and the mechanic's opinion was that the HT leads, coil pack and spark plugs should be replaced for £116. He is a respectable guy so I'm not concerned he is trying to 'do' me by suggesting more repairs than necessary.

A few thoughts;

1) Do you guys think this would solve the misfire issue? Do all 3 of those parts need replacing?

2) I've never done any mechanical work on a car, but I'm not afraid to try. Could I buy a coil pack, leads etc and replace them myself? I popped the hood and couldn't for the life of me find what looked like a coil pack...

3) Is the misfire actually being caused by the super unleaded fuel? Seems a strange coincidence that the problem started here

Thanks for any replies

ht leads are connected to sparkplugs one end and coil pack other end.so coil pack is on the right end of engine

i would buy and try 4 sparkplugs and coil pack first.you will need a sparkplug socket etc. coil pack held in place with 4 torx screws.

Hi Kurt, welcome to the forum buddy.

I would recommend that you invest in a Haynes manual, as they're worth their weight in gold. You could probably buy a second-hand Haynes manual from eBay for a tenner. I bought mine brand new. It provides you with clear instructions on everything, from how to remove an oil filter to removing your gearbox.

You would need to invest in some tools before you can tackle this job, unless you have a mate or someone you know who can lend you the tools for the job. You will more than likely require a spark plug socket for starters, along with an extension bar and a ratchet.

^There's an image if it's any use to ya'. A Haynes manual for your vehicle will show clear pictures and descriptions for this job. Here's a link to the manual for sale on eBay (it should be the right one for your car): http://www.ebay.co.uk/itm/Haynes-Workshop-Repair-Manual-Ford-Fiesta-02-08-/390521347395

Hi Mike thanks for the reply

I will order one of those manuals tonight, looks like it could come in handy. Do you think a coil pack will be enough, or do i need to replace the cables too? or should i try one thing at a time?

Unfortunately the picture you posted isn't what my engine looks like. It looks more (but not exactly) like this:

http://silverlake-breakerimages1.s3.amazonaws.com/BreakerImage_38ac2bda-b86d-4860-bb58-19b20cf1cdb0.jpg

I've peered inside and cannot find anything that looks the thing being pointed to in your picture.

ht leads are connected to sparkplugs one end and coil pack other end.so coil pack is on the right end of engine

i would buy and try 4 sparkplugs and coil pack first.you will need a sparkplug socket etc. coil pack held in place with 4 torx screws.

Hi Ian my engine looks similar to this :http://silverlake-breakerimages1.s3.amazonaws.com/BreakerImage_38ac2bda-b86d-4860-bb58-19b20cf1cdb0.jpg

Cannot seem to find the coil pack unfortunately. Do I need to unscrew a panel or something?

The pic you show has still got the airfilter housing still in place, that big plastic box hiding the leads and coil pack.

2 10mm headed bolts you will see holding in place, and a rubber breather hose to disconnect, pull intake pipe off, then pull it off its rear mounting pegs.2 minute job to take off.

Allways check or replace sparkplugs when replacing coilpack as they can cause coil pack to fail in the first place,

As mike earlier said you will need socket , ratchet , extn bar To remove plugs.