hiya people,
im kinda stuck we have a ford focus 1.4 2002 model engine keeps missing underload, its had new coil,temprature sender unit, and new plugs, i thinking it might be electrical, maf? lambda?? any ideas??

 

I'd start by changing the fuel filter unless done so recently, then check the co.
tabetha

 

thanks for the reply tabetha why would you say its that i no i say its boggin down 'underload' but i wudnt have throt that would cause it to behave like it is its not spluttering or anything its jus like hitting and missing when u poot your foot down, cheers

 

It could do, there are a number of things it could be such as BOSCH plugs, these can cause the issue, as they can track chronically in zetecs, the leads can cause it, on the earlier zetecs leads ford used silicone grease inside the plug caps where it slid over the porcelain.
I suggest first take the plugs out and look at the porcelain part and see if it has any lightning type black streaks on it, as this is tracking, and is another thing to look at.
tabetha

 

have the plugs been gapped correctly?

would be worth getting a fault code reader on it.

 

sorted guys it was the leads, well atleast it wasnt anything major thansk for replys

 

good 8) glad it was an easy fix