i have a ford fiesta 1.25 zetec and its got an engine misfire, its had the coil pack, leads, plugs changed and crankshaft sensor but still the same, it has a spark at leads 2 and 3 but not at leads 1 and 4 im guessing the problem could be electrical? any help would be much appreciated thanks craig

 

Try another coil pack.the new one could be faulty.

 

Either you are unlucky and have another duff coil pack although unlikely I should think, you have a connection problem or I seem to recall this problem is caused by the PCM (There are two sides to the coil pack each firing two cylinders)

Normally when the coil packs faulty the problem gets worse when the cars hot as they break down under heat.

Martin

 

I have to agree with marty , some time ago we had a fiesta with the same problem , swapped coil , still missing , removed PCM and checked wiring from PCM to coil , all ok , then we replaced pcm and it was ok , must of been a faulty driver within the pcm , but just double check everything before going down the pcm route .

They have a tamper proof bolt holding the wiring in so you will need to drill that out to check wiring , and dont forget once you have swapped PCM's you will need to recode keys , unless you get the matching key with PCM then you might get around it .

Hope that helps

 

ok thanks all for your help, where do i find the pcm and what does it look like? sorry for sounding silly but what is the pcm anyway? thanks again craig

 

PCM is Powertrain Control Module , it is just the engine ECU , and it depends on what exact age and model to where it is mounted , let me know what it is and will try and help

 

its a t reg 1.25 zetec fiesta, i take it its not the main ecu then? thanks again craig

 

Yes it is the ECU, it will be an EEC model, I am not sure on your car, but it may be located behind the drivers kick trim panel?

Martin

 

ok thanks again i will have a look tomorow, i wasnt sure when you said pcm if there was more than 1 ecu, ive seen a few on ebay with key and transponder but there seems to be a lot of different part numbers and code names.

 

i have tested the wires form the ecu to the coil today for continuity and all is fine so its looking like its the ecu at fault, the ecu was located behind the plastic panel in the passenger footwell, does the ecu numbers and code name have to match exactly? as im going to try and get an ecu with a key to save money on having it all recoded? thanks again to all who have helped so far.

 

Yes you want an identical replacement and one for that capacity engine as well as the mapping will be different if it's for another engine, getting one with another key will make no difference as it isn't going to work with your lock set. However having the keys may help in that it will make it easier to pair you keys to it. Does your key have a red transponder in the top of it?

Martin

 

Ecu's can be repaired. Maybe inquire at bba-reman?

 

yes it does have a red chip in the key, will it not work if i have a new ecu with the key? as in will it start? i can always buid the locks to fit the key, i cant find a replacement that has the exact code name and numbers at the moment, so is it possible that one for a 1.25 zectec would work if recoded? thanks again.

 

yeah i might have to go down that route, do you have a number for who you have quoted? thanks.

 

Google and then search for bba-reman?
It's the first entry and it's a uk based company.

 

ok thanks for that.

 

thanks to all who have helped so far but i have another question that hopefully someone can give advice on, i need to get another ecu with key or just red chip ive tried ebay and partfinder but no one has one that exactly matches the part number ive got, is it possible to fit another ecu from a fiesta 1.25 zetec? and will it work correctly? if of course i get the key and or chip that is matched to that ecu? iv looked into getting my ecu repaired but had a few quotes from companys and that route would be expensive. the car i have is a 1999 fiesta 1.25 zetec.

 

Don't quote me on this but I should think so as long as it's for a 1.25 but find out for definate, but it may have the later revision of PATS (With the blue transponder opposted to the red you have) these are totally different systems.

With your version of the PATS if you have a red transponder then you need the red master key as well in order to program additional keys, if you don't have this you need "Ford's machine" in order to program keys.

If you get the ECU with the later version then provided you get a key/keys with it that are already paired to it then you may be able to transplant the blue transponder from that key to your key (Replacing the red transponder) and this will work

Obviously if you get 2 keys with it, you will need to get another key cut, as the red master key will be useless.

Martin

 

ok thanks, how could i find out for sure if it would work? mine has the red chip in the key so if i got an ecu with key and red chip i could just swap the chips in the key, im not too concerned of having more than 1 ignition key at the moment so thats not a problem, all the ecu's ive found for sale so far are different part numbers and code name as in slob, jugs, jeer, mike etc mine is farm and different numbers, but all these are listed for a fiesta 1.25 zetec engine,

 

Yes if you get an ECU with keys you can just swap the transponder, tbh to know for sure re whether the ECU would work you would need to speak to someone who had intimate knowledge of the ECU'S as they know exactly what the differences are, my thinking is so long as it's for the same engine it should be fine to run that engine but as I say that is my thinking, not knowing.

Martin

 

just want to say thanks to all who have helped with the misfire problems, i managed to get a second hand ecu with key and chip which exactly matched my ecu numbers so it was just a straight swap for the old one and just had to swap the chips in the keys, it now runs fine and was a lot cheaper fix then having my ecu repaired.