As above this has been going on some time and I cannot get to the bottom of it. When the engine is cold and only for a very short period of maybe 1 min after starting when you pull away under load the engine misfires and the car jolts about trying to stall. If you rev it enough prior to pulling away it will be okay. By the time you reach the end of the road about 50m and pull away again it's fine. If you are on a hill or stuck on a bump and try and pull away no chance! I have had to rev it and slip the clutch to try and drive up the driveway into the garage with it popping and banging all the way.. drives fine otherwise! What I noticed in the recent colder weather though is when the air temp is 5 degs or below then you don't seem to get this misfire problem? Very curious. What do we think. Could it be temp sensor. Clearly it is something temp relative during a very short window at start up that is effecting fuelling. I would say it's going very lean.

Appreciate any input.

I just borrowed an OBD fault reader this is some of what came off. I believe most relate to the misfire..not sure if any help pinpoint the cause?

============================
OBD-IIOBD-II
DTCs: 220
----------------------------
P111A(00) [0x111A00]
Status: Pending, Confirmed, Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P0301(92) [0x030192] Archive (inactive)
Cylinder 1 - misfire detected
Cylinder #1 Misfire Detected
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P0300(92) [0x030092] Archive (inactive)
Random/multiple cylinder(s) - misfire detected
Random Misfire Detected
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P0325(01) [0x032501] Archive (inactive)
Knock sensor (KS) 1, bank 1 - circuit malfunction
Knock Sensor 1 Circuit Malfunction
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P0330(01) [0x033001] Archive (inactive)
Knock sensor (KS) 2, bank 2 - circuit malfunction
Knock Sensor 2 Circuit Malfunction
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P0506(26) [0x050626] Archive (inactive)
Idle speed control (ISC) system - rpm lower than expected
Idle Air Control System RPM Lower Than Expected
Status: Test failed since last DTC clear
----------------------------
P2297(96) [0x229796] Archive (inactive)
Heated oxygen sensor (HO2S) 1, bank 1 - signal out of range during deceleration
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P2298(96) [0x229896] Archive (inactive)
Heated oxygen sensor (HO2S) 1, bank 2 - signal out of range during deceleration
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
P2A03(36) [0x2A0336] Archive (inactive)
Heated oxygen sensor (HO2S) 1, bank 2 - circuit range/performance
Status: Test failed since last DTC clear, Test not completed during this operation cycle
----------------------------
U0284(88) [0xC28488] Archive (inactive)
Lost Communication with Active Grille Air Shutter 1 Motor Module
Status: Test failed since last DTC clear
----------------------------
P065C(09) [0x065C09] Archive (inactive)
Generator - mechanical fault/performance problem
Status: Test failed since last DTC clear
----------------------------
P2617(1C) [0x26171C] Archive (inactive)
Crankshaft position (CKP), output signal - open circuit
Status: Test failed since last DTC clear
----------------------------
P0217(4B) [0x02174B] Archive (inactive)
Engine over temperature condition
Engine Overtemp Condition
Status: Test failed since last DTC clear
----------------------------
P165B(92) [0x165B92] Archive (inactive)
Status: Test failed since last DTC clear
----------------------------
P060A(47) [0x060A47] Archive (inactive)
Engine control module (ECM), monitoring processor performance problem
Status: Test failed since last DTC clear
----------------------------

Those codes are all old (inactive) so they don't tell us much.

A 51 plate Focus doesn't have a grille shutter either.  Did you mean 61 plate?