Focus 1.6 2006 rough

[wjwren]

I have a focus 1.6 2006 when driving and the engine is doing about 2000rpm the car jerks slightly. I changed the coil pack HT leads and sparks & air filter and problem is still there. Also the ht leads when pulled off the sparks are coated in a golden like powder - is this rust maybe?

[S0 What]

Possably? most likely your screen washer jets are letting water into the bay, it runs under the air filter and sits in the head where it shorts out the plug leads, well known problem on the focus and fiesta.
I had an 03 plate fiesta in last week and the head was literaly full to the brim with water (been standing a few weeeks) and the plugs were rusted, even the threads 90% to the tip!