glendowbakin

Hi, i have been having a problem with my 1.6 focus (petrol 2002) the problem is that when i start it up in the morning it runs really rough and if i touch revs it conks out, when the car is warm (after a minute or so) it runs mint all day unless i leave it to get really cold and then same again, its had redex, new plugs, new ICV, throttle body cleaned and new air filter. There is no engine light on and like i say it only does it when cold, it ticks over at really low revs and feels like its gonna cut out. when warm it runs mint and idles perfect. The only thing that i can think if it being related to is some muppet jetwashed the engine and when i was changing the plugs i noticed there was water down the plug wells, so i soaked it all up before i changed the plugs. I noticed there is a temp sensor in there but the guage appears to be working properley so unsure if thats related or not? Does that sensor do the temperature guage or the ecu or both?? It was covered in water but now dry. May be unrelated to the fault. It feels like starting a car with out pulling the choke first if you know what i mean?

Any help apreciated

Thanks

Glen

RichieST

iTrader: (2)

That sensor in the spark plug well gives the engine temperature reading to the ecu, which then in turn goes to the dash clocks. It's pretty vital for smooth running that this sensor works! I would try removing the plug and making sure the terminals are clean and dry, could even give it a blast through with wd40 or something. If things don't improve I would try changing the sensor, or even pay ford for a live scan of all the sensors, to see what reading they are giving. When you start changing parts on a hunch then it can get costly!

glendowbakin

ok i will give it a good clean today, im 90% on it being this sensor but it shows half temp on the guage and goes to the bottom of guage when cold? might be interference from the rusty crap that all over it, i will post results later

RichieST

iTrader: (2)

Thing is, if this sensor is giving an incorrect reading, the ecu will THINK the engine is at the correct temperature, so the gauge will act normally, but in fact it isn't, so it won't run properly.

So for example, the engine temperature is 50 degrees, the sensor reads that it is 90 degrees, the gauge reads normal, the ECU fuels the engine for 90 degrees, when in fact the engine is stil 50 degrees so it doesnt run properly.

glendowbakin

ok well if you are correct i think i have found the fault, hope so i only had it for a few months and have not even paid my 1st year finance yet

Thanks for your help i will let you know later today if it has fixed it.

RichieST

iTrader: (2)

Hope it does sort it! Can't guarantee but it's the most likely I'd have thought.

tabetha

It wouldn't hurt to clean the MAF as well and reset the KAM by pulling the fuse for a few minutes.
tabetha