HI,

Our focus has been running fine but has just developed a misfire/roughness and loss of power. It is drive-able but sounds rough and feels awful. Initially the Check Engine light was flashing, on 2 seconds approx / off 2 seconds approx, now it is permanently on.

I have checked for air leaks, loose connections, nothing appears loose or dropped off, plugs look fine and compression is good across all 4 cylinders.

Any ideas what I should be looking at next, any obvious suspect items which could casue this?

Many thanks,
Andy.

 

It could be the coil. I've changed them in every focus I've owned.

 

I guess you can't test it?

I have seen warnings about using non-genuine ones but Ford ones seem to be over £100! Lot if it isn't the problem.

Some on the bay for about £30.......

 

I got a spurious one (cheapo one) and it failed. If your handy with a multimeter you could test the voltages across the terminals.

 

Handy enough I reckon

Do you have any values?

 

OKay, here is where I am, coil is the issue, I think:-

Resistance between 1 and 4 on coil pack is 10.45 kO
Resistance between 2 and 3 on coil pack is 10.32 kO

Seems okay..............

Leads are 1: 4.65kO, 2: 4.18kO, 3: 3.38kO and 4: 3.33 kO

Seems okay..............

But did a spark test on each tower from the coil, using same plug and lead:-
1 - Big Spark
2 - Very weak Spark
3 - Very weak Spark
4 - No spark

New coil required then?

Any outlets for a cheap OE one???

Thanks for help so far.

 

It should be easy to notice whether it's miss-firing or not.

A coil pack is two coils in a pack, each running two cylinders, so if one has gone then it will misfire on two cylinders 1 or 3 or 2 and 4.

Martin

 

Hmmmm, that doesnt explain what I am seeing above, deffo big spark on 1, very weak on 2 and 3 and nothing on 4...............

Have repeated a few times now and get same every time????

 

Perhaps go scrappy get some ht leads? And have you tried new spark plugs seems obvious but just thought id put that out there lol

 

Actually ignore me didn't read your post properly

 

New coil pack fitted at the weekend, got a Visteon one which I have read are the same as the Fomoco branded ones, works a treat and all is well

Here is where I got it from, really helpful chap:-
http://www.ebay.co.uk/itm/390379132068?ssPageName=STRK:MEWNX:IT&_trksid=p398 4.m1497.l2649