Mechanics

FIRING ON 3 CYLINDERS

2002 Ford Focus

Engine Performance problem
2002 Ford Focus 4 cyl Two Wheel Drive Manual 19824 miles

I have a ford focus 2002 1600 ztec

My engine at the moment only fires on 3 cylinders no 1 cylinder does not get a spark from the distributor cap however the other 3 do. I am guessing that the engine management module is at fault.

Can anyone confirm this?
Avatar
Philip john
February 22, 2009.



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)?

Dave H
Feb 22, 2009.
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?

Tiny
Philip john
Feb 24, 2009.
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 !

Dave H
Feb 24, 2009.
Thanks again for that.

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

Tiny
Philip john
Feb 25, 2009.
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!

Tiny
Philip john
Mar 5, 2009.
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

Dave H
Mar 6, 2009.
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

Tiny
Philip john
Mar 8, 2009.
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


http://www.2carpros.com/forum/automotive_pictures/266999_AAA2_67.png


Dave H
Mar 8, 2009.