Got an odd one with my 2001 1.6 Zetec Focus.
Trying to accelerate with anything other than light throttle input (less than 1/4 pedal travel) means the car stutters and loses power, if you back the throttle off a bit it picks up and runs as normal.
The engine management light flickered a few times and is now on all the time.
My thoughts are that its either throttle position sensor, as the fault seems to happen at roughly the same throttle position, or possibly MAF or plugs / leads or even coil pack.
The coil pack is only about a year old, but im not ruling it out.
Anyone else had this or got any useful suggestions?
Thanks
Plug in a proper diagnostic tool that will work on a Ford PCM (Power Control Module) This will give you a fault code and description, then it will hopefully point you in the right direction of what the problem might be.
I think I may have worked it out.
Car was given a good going over yesterday, including the underside of the bonnet.
The problem didnt start until I went round a roundabout a little too vigorously.
I think water has come out of one of the bonnet channels and is sitting in the plugs bores in the head, causing the spark to break down at higher loads.
Bugger just noticed I spelt Focus wrongly in the title, sorry! 😳
If you were near Peterborough I'd lend you a diagnostic unit.
Had the same misfire, diagnosed coil pack from the computer code.
Had something similar twice on my 55 zetec. First time water had got in the engine via the core plug. 2nd time water from the leaky windscreen jets had ingressed on spark plugs and leads.
Hmm, took all the leads out, plugs out and coil pack out. All clean and dry. It now drives better and you can drive through the still present hesitation.
No warning lights either.
I'm leaning towards leads.
My 04 did this and needed a new coil pack.
My 04 did this and needed a new coil pack.
Seriously!
Yep, that what I was told was replaced and it's ran fine since. But the Op's problem could be something else I haven't got a clue about mechanics.
Sorry, wasn't commenting on your post Kuco. I was (badly) saying that I had exactly the same problem, with same resolution, on same year car, as you.
Spooky 😀
Swop the leads and plugs first, they are renown to give grief and are cheaper than a coil pack. Use silicon grease on the inside of the plug leads ( not a lot, just a smear). This stops the water causing an arc to earth and misfiring .
If you've got a laptop, and you like fannying around with things, I can recommend this:
Reads and clears codes, and pretty simple to use. Should be compatible with your model I think, though maybe worth checking. Paid for itself many times over with mine.
Also you can use it to get a live feed from the console with all sorts of interesting sensors and doobries, which isn't often very useful, but is pretty damn fast and furious. Leave it on the passenger seat, every so often shout NOOOOSSSSSS and mash the enter key.
Leads and plugs are next.
Coil was replaced about a year / 18 months ago, so I'll rule that out for the moment.....
Just had a thought, I could swap out the leads from our '99 Mazda 323 and see if they make any difference.....
Coils in those especialy some of the cheaper patern ones are prone to being shit.
Swapping leads over made no difference either. Plugs and coil next....
Had the same issue with a 1.6 Fusion (presumably the same engine)
Due to it being needed for work and the dealer not being local, I just bought plugs, leads and coil pack in one go with an agreement that if the plugs sorted it it, I could bring back the more expensive coil pack.
It was the coil pack.
Advice on the internet was to get a genuine Ford one as apparently the 1.6 can be a bit fussy with a pattern part.
Plugs ordered, then if they don't sort it a genuine Ford coil is next. Failing that, garage!
Nothing quite like the parts cannon to suck up money 🙂
Interesting. Read last night that the plug gap was changed from 1.6 to 1.0mm at some point in the past. Regapped the existing old plugs and there's a definite improvement.
Hopefully new plugs will help further.
I'm wondering if the plugs being incorrectly gapped have harmed the coil? Or if the plugs are just old and not bridging the gap as well as they should.
Whatever that's a step in the right direction.
Yay, problem fixed!
Apparently spark plugs with a service life of 37,000 miles don't perform as well at 73,000 miles!
Cost £8.16 for 4 Bosch plugs.