Throttle body problems-Ford Escost Finnesse 1998, 1.6 ltr, Petrol

[pbs6vas]

Hi guys,
I am a Newbie from Halifax, England.This is my first post.Sorry for the long post. I changed the fuel filter last week with fords brand New.Had problems since then.Very low idle and lack of power especially while climbing even mild elevations. Changed the fuel filter..............yesterday with halfords brand.Better than b4 but still lacking power while climbing elevations.

I forgot to tell you. My car got idling problems( high idle at start).I requested the garage guy(MOT centre) to clean ISCV 6 months back.That guy adjusted some screw in the throttle body housing with philips Screw driver to bring the idle speed down instead of cleaning the ISCV. He said that is the only way of doing it. It didn't effect the idle speed but since then I observed lack of power of the engine.
but last week b4 changing the fuel filter, i cleaned my ISCV. ISCV is full of dirt and cleaned it throughly. The idle speed improve much.But after changing the fuel filter, its idling at lower rate( couldbe between 700-800-no tachometer on my car). I am wondering whether is it the cause for lack of power??.Do i need to readjust the screws in the throttle body to bring the power back??????????.If so please explain in detail.My knowlegde is very basic.Can someone shine light on this please.Thank you very much guys. Cheers