[suppa]

Hi,

I got a Fiesta 2004 LX 1600cc Petrol Auto, has done 230K

This April, I got an idle vibration, I was stopped at traffic light, after a while ,the engine started to shake, and rpm is not stable up and down between 800-500, the engine management light came on, I put my car to mechanic, and the code showed one of the cylinders (Cylinder 3) was misfire.

I had changed Coil, Spark PlugX4, LeadX4, but still can't fix the problem. Later, we reversed the position of fuel injector of cylinder 1 to 3 and the code changed to "cylinder 1 misfired". Finally, I put a second hand injector on my car, and the engine management light was gone, the car went smooth for months.

But 2 weeks ago, my car started to have idle vibration again, and more, it had a rough start too, after ignition, the rpm to 1000, drop to 500 then misfired, I need to put my acc pedal to keep the engine running over 2000rpm, to avoid misfire, after that, the car run fine, no engine management light came up, only idle vibration and rough start.

Anyone have some ideas what sort of problem cause to idle vibration and rough start?

and I have some thoughts as below
- Fuel Injectors problem
- Fuel Filter and dirty Fuel Tank