Good afternoon All
I am new to this site as i just bought a Ford Fiesta three days ago as I went on holiday. It is a 2007 model 1,4 Duratec engine.
When I bought the car the owner told me about the rough idling and that the diagnostic result indicated that the ECU is faulty. I drove the car home from 750 kilometers without any problems. I could keep a steady 120km per hour and could overtake at 130km per hour. No overheating, temperature was steady at 80 degrees the whole trip.
No 2 Cylinder is the problem. There is fire at the spark plug. I changed spark plugs, changed the spark plug wires as well. Same problem. When I remove the Spark plug cable one by one, there is no change in cylinder two. I do not suspect a faulty valve or rings or gasket as the car performed well on the drive home.
Please help as I really like this car

nazeem

coil pack, ? ECU isn't likely to be faulty, you need to get the codes read to see what they point to, rough idle could just be dirty throttle body or air filter.

It would be strange if the ECU were faulty.

The engine needs 3 things to work. Air, fuel and spark.

Spark is the easiest thing to diagnose - Disable the fuel pump, then remove the spark plugs one at a time, hold each against the engine block (or any earth) and crank the engine. If the spark plug generates a spark, everything in that link is fine. If you get a plug without a spark, it could be a faulty plug, faulty ignition lead, or if you swap everything and you still have a problem, it's got to be the coil pack.

If you've got sparks on all plugs, then fuel isn't getting into the cylinder. This normally indicates a fuel supply issue, either an injector, or a blockage in the fuel rail.

Air - well, if 3 other cylinders are getting air, the fourth will as well - unless you've sucked a sock into the intake manifold and it's blocked (highly unlikely).