Righty ho,
So, dropped the 2.0ltr in and its not running right.
It's misfiring throughout the rev range, but most noticable at idle. Misfire at cold and warm.
Been out tonight and tried a few things, as follows:
1) replaced HT leads - No change
2) replaced coil pack - No change
3) replaced TPS - No change
4) checked hose from PCV to inlet sandwich - replaced hose with slightly better fitting one - No change
5) Unplugged ECU Coolant temp sensor and cleaned
6) tried unplugging injector wiring whilst engine running
cyl 1 - engine stopped
cyl 2 - no change
cyl 3 - engine struggled and nearly stalled
cyl 4 - engine stopped
Therefore pointing to Cylinder 2 as the cause of misfire.
7) moved onto plugs cylinder 2 was covered in black soot - implying over rich/no comp I believe
8) cleaned and swapped plugs from cylinder 1 and 2 - Still missing but retried injector plugs
cyl 1 - struggled but didnt stall
cyl 2 - struggled a bit but didnt stall
cyl 3 - engine struggled and nearly stalled
cyl 4 - engine stopped
During all of the above, any plug that was unplugged had WD-40 sprayed in it also.
It is running a bit better than when I started but still nowhere near where it should be.
So, it looks like the plugs may be a bit dodgy, they are FoMoCo ones from my Si, so done 20-30k and due a change, but maybe also compression. Going to go to Halfords tomorrow and buy plugs and a compression tester.
Does anyone have experience of the Gunson one Halfords sell, does it work ok with the Zetec?
Also, does anyone have any clues to look for the cause of sooty plugs should the compression come out ok (fingers crossed

)
Sorry for the long winded post, but wanted to get down everything in one place.
Cheers
Paul