Help - bizarre fuel problem

Hello,

I have a bizarre issue with my car and need some advice...

It's an old 2002 1.6 petrol Focus auto - just a work horse to get to work etc.

The other day it wouldn't start properly having worked fine the night before - with a bit of throttle it would start but ran really rough, as if running on 2-3 cylinders with loads of blue petrol smelling exhaust. In the end I found it was a leaking fuel injector. Injectors out and ignition on number 1 squirted fuel out and number 3 was damp while the other two stayed dry.

I ordered some replacement ones off ebay and fitted them today - tested and no leaks whatsoever. 98MF-BB 9F593 - same as what's in my car.

Went to start the car and pretty much had the same problem. Removed plugs and they are black and wet smelling of fuel. I figured there was some fuel sitting somewhere in the intake manifold so left the plugs out for it to dry out. Turned the engine over with no plugs in and fuel pump fuse out to try clear out any excess fuel. Unplugged the battery for an hour or so and cleared the ECU of any codes.

Now this is where it defies my logic. Normally with the fuel pump fuse out it starts until the fuel pressure goes and then cuts out and cant be restarted... which makes sense.

So now with the pump fuse out it will idle a little rough but smokes and any throttle kills it pretty much instantly. It will idle for a good few minutes before eventually dying but can be restarted.

Fuse in and it is as it was before- almost impossible to start, bit of throttle and it does but as if its running on 2-3. As soon as there's no throttle it cuts out.

In both cases the plugs come out black and fouled and the exhaust smokes blue/black and smells strongly of fuel.

My first guess was there's a little fuel pooled somewhere that basically lets it idle with no fuel pressure however it doesn't seem to be drying out etc.

Anyone had this before or have any suggestions before i start throwing money at a proper mechanic?

Thanks in advance and apologies if this is under the wrong part of the forum!

FG