Focus 1.8 petrol lacking power

[smithma0]

Hi there

My 2000 1.8 Focus Zetec is lacking power under load over 3500rpm. It will not achieve more than 4500 in third. There is also a 'pinking' sound under load.

I suspect the afm may be at fault. Have tried unplugging it and get the same result. Is this an indicator is is faulty?

Thanks for any help.

[budgie smuggler]

What do you mean by 'pinking sound' ? Is it a mechanical knocking noise?