Engine Misfire

A photograph / description of the location of the water outlet housing would be great if you wouldn't mind-gonna have a crack at it tomorrow...fingers crossed. Really appreciate your help

Not sure if the sensor on my focus engine is in the same place on the fiesta/puma 1.6, probably not, but thought this might help. This is a diagram of the 1.6 in a focus, the temp sensor is by the spark plugs, number 4 in this pic



In the puma 1.7 its in the water outlet under the coil pack. Heres a pic, sorry its not very clear, its lined up next to other spare engines i have, but if you find the coil pack, you should be able to make out where it is.



My focus 1.6 doesent have any sensors there, so youll have to let us no if you have any sensors there or not.


On another note, if your car has 2 lambdas (normally a blue plug and a green plug), then if one was gone, there would definitely be a fault code. The fault code is generated when there is a either not enough difference between the 2 readings (they go either side of the cat, so this would indicate a faulty cat), or if the difference is too big, indicating on of them is at fault, and its highly unlikely that both lambdas would go at the same time. Are you sure it has 2 lambdas??

If its a 2 lambda model, that leaves faulty injector, or fuel pump in the fuelling system, although the ecu would pick up a faulty fuel pump as a lean mixture. It could be 1 or more faulty injectors, all the ecu would do is overcompensate for the faulty injector by increasing the pulsewidth of other injectors, it only knows a collective air/fuel ratio, so if one cylinder is lean, but others are slightly rich, the ecu wont know.

next cheapest thing would be a compression test, if its not a fuelling issue, and its not a spark issue, then the next thing is low compression.

Im running out of ideas here!!! :?

yeah its defo under the coil pack,replaced mine months back bit of a faff to do.i thought it was near the plugs but thats the CYLINDER HEAD TEMP SENSOR

Ah OK well on inspection it turns out that my car does have two lambda sensors and no light-so based on what has been said-I should rule this out?

I'm still not convinced that it's not a timing issue...seems so coincidental that it started after the belt and pump change. Might have a look and check that the timing isn't one tooth out or something-if not compression test and fuel injectors are next-so frustrating!

I'll keep you all posted and of course any further ideas are welcome

Thank you

I'm not sure what sort of job changing the fuel injectors is-can I buy a new loom and replace the lot? Just weighing up my options...

Thanks

If you are just replacing the injectors, and not the rail, they come out quite easily, you just need to take the plugs off them, take out the 2 bolts that hold the rail on, & take off the metal clip that holds them in the rail. if you are replacing the whole rail, just unclip fuel pipes, remembering which one goes where, and then take out the 2 bolts that hold the rail in. I'm not sure if there is anything else on the 1.6. Just don't do it straight after the car has been running as the fuel system will still be pressurised.

If the engine has not been timed up right, then it generally wouldn't run right anywhere in the rev range, and wouldnt idle right unless it was a VCT engine. That's not to say its not the timing, I've never experienced incorrect timing, but I can't see why it would give you faults in only certain parts of the rev range or certain speeds. If it was slightly out, you'd just be down on power, if it was a fair bit out, the car would drive crappy.

Are you sure it's a misfire?? And is it always at the same speeds or is it intermittent? If it happens at different revs or different engine loads, then it could be a loose/bad earth. Check all the earth straps between battery neg and body, & between body and engine. Also worth checking the live is securely fixed while your there. If there is and electrical fault, or too much resistance, it could cause the spark to be too weak, but would be on all cylinders not just one.

Earth straps are often overlooked, also petrol? have you changed supplier? Have you tried a fuel line cleaner?

have you checked for vacuum leaks, check this out lol http://www.youtube.com/watch?v=zMok2y05jNE

Hi there, just an idea here: look at the 3 rubber hoses that recirculate the air inside the engine. i had problem with misfiring and those 3 hoses were tear on the inside of the bend, i change them and work very nice after. Good luck

This threads over 2 years old!

Holy necropost batman!