Hi all,

I have a 2004 1.8 Zetec Petrol Focus.

ISSUE: Every now and then the car will stutter which seems to happen primarily in 3rd and 4th gear and sometimes if I push hard on the accelerator (in any gear). On 2 occasions I have lost all power and have had to be towed. I researched a lot, read lots of forums and had some work done. Seemed to be OK for a while but is now stuttering again and I am now conscious that it may break done again. The engine warning light has never come on at all (even temporarily) and I have had a mechanic plug in to check for error codes and none have shown.

WORK I HAVE HAD DONE:
1. Oil change, Coolant change
2. New oil filter, new fuel filter, new air filter
3. New spark plugs
4. New ignition coil
5. New Catalytic converter
6. I also tested removing the MAF Sensor and the car kept running. It looked clean anyways, but I sprayed the MAF in contact cleaner, let it dry and then reconnected it
          6a. I have read conflicting information stating that if the engine doesn't cut out when the MAF is removed it is faulty?
7. It passed a MOT about 2 weeks ago with no advisories (no emissions issues)
8. I have also added a fuel injector cleaner to the fuel and SEAFOAM Carb cleaner (on different full tank fillings)

OTHER INFO THAT MIGHT BE HELPFUL:
1. Car seems to be running rich a little but...
2. Has a low idle (below 1000)
3. The car does give off a smell sometimes (not an egg smell or a fuel smell - more of a plastic smell) - I have tried to work out where it is coming from in the engine bay but can't isolate it
4. Separately I have had the clutch changed a few month back (before the stuttering) so it isn't the clutch

Is anyone able to give me any advice on what the issue could be given the above info?

Thanks much in advance,
Matt.

It might be worth changing the tps. It could have a dirty contact mid position. 

The graph shows an intermittent tps with a bad contact at mid range. This will cause a judder when driving. If you can take the tps apart you can clean it or try and spray lots of electrical contact cleaner over it hoping some will get inside onto the contacts.

 

Thanks very much Kevin - I will give that a go in the meantime and order a new part as a back up given it is only a tenner.