2002 Ford Focus Firing on 3 cylinders

the 2002 ford focus does not have a distributor .. it is fitted with a coil pack (one large coil) or coil on plug system (one coil on each plug) ??

Thanks for that!!

For the last 10 years I’ve been running a diesel, so I have not kept up to date with technology, but I assume it will work in roughly the same way!!

If the HT lead had a break it would cause this fault right? So can I do a continuity check of the HT lead? Or does this lead have a built in resistance needed to make the spark in the 1st place?

I believe your vehicle is fitted with a coil pack .. black box looks like the old distributor cap ?? you cannot really test the leads .. you are better testing for blue spark with a spark tester .. if it is orange or no spark swap with another lead onto that plug and retest to see if you get the same result ? if you do then its not the lead ... remember to trip the inertia switch so the vehicle does not start while cranking !!

Thanks again for that.

Ill give this a go!!
And ill let you know how i get on.

At the weekend, I changed the Spark plugs, HT leads, and it did not fix the problem.
Therefore, it must be the HT coil pack itself.

Ill have a go at changing it before taking it to a shop!

BTW, the HT leads have a built in resistance of 4-6 K ohms so even new ones will fail a continuity test!

coil pack change is easy to do .. just remember to get the leads back in the same order ! I did say you could not check the leads .. let me know

Success!

I changed the coil pack (myself) made a drawing of the spark plug lead positions (so I knew what went where) and it worked fine!

Apart from the screws that ford had used to secure the coil pack they, were the star drive type that rounded off quickly, so I had to replace them as well. After I had to smash the tops off with a sharp chisel.
It was a good job that I had some M5 screws to replace them with!

Thanks to this site, I got all the help that I needed.

Thanks again guys!!

Phil

Hey Phil No problem .. that's what we are here for !! feel free to leave feedback using the link at the top of this box ... and spread the word of our site to friends and family ... the Torx screws are a pain in the A** ..LOL .. congrats on a job well done !! and remember we are here if you should ever need assistance again ! Happy Motoring