Hi, i have a mk3 fiesta with a 1.8l turbo diesel, i think the engine came from an escort.

Anyway it has a Bosch fuel pump. The problem is i set the idle to around 800 rpm like the Haynes manual suggests however it's not always idling at 800 rpm. The problem started with the car sometimes idling properly other times idling slow, slow enough to make the car shake and bits of the interior fall off! so i increased the idle and opened up some fuel. It worked fine for a couple of days however now the problem is the opposite it idles good or too high.

i reduced the idle and fuel again and it worked for some time but the problem came out again still it idles at 800rpm or 1500rpm (either or) what i have on doesn't effect this (lights on or off engine fan on or off) nor does the engine temperature. Sometimes i'm driving put the car in free and idles good, drive a bit and it starts to idle high, then good again.

I also noticed that it is not affected if i m driving uphill downhill or on flat road, also the amount of fuel in the tank doesn't make a difference.

Oh the cold start thing that makes the engine idle a bit faster till it warms up is missing a piece, however it was like this when i bought it and up until this summer i haven t had this problem.

I' m assuming the problem is from the fuel pump or fuel delivery?? Oh and the engine makes a loud noise but i don't know the word used in english, it's like metal clanking of sorts?? don t know, however it did that noise since i bought it and my brothers 1.8 has it aswell so i'm assuming it's normal?