wont start when cold, if starts is lumpy and engine hunting!

[desperate to fix my 1.6]

please please PLEASE somebody help meeeeeee!

firstly I must commend this sites organisers as a number of occasions ive solved issues saving me money - great work guys!

OK then my 1.6 is really ill! she starts on the 5th attempt most mornings, and i let her run idle for about 5 mins as its sometimes impossible to drive when cold. upon starting her up, i have to hold the revs at circa 1.2k as she cant idle when cold, she hunts and hunts until she dies completely.

so 5 mins of idle (1.25k revs) and I'm pulling off but feels almost like the gas pedal don't respond, floor it (not when too cold tho) and nothing then suddenly the engine gets power - quite retarded - unpredictable too, soo dangerous at roundabouts when pulling out, I've had too many near misses to be complacent now.

so were driving now, the engine is warm, heater blowing out nice warm air, engine still retarded but less often and stopped at roundabouts in neutral the engine can idle ok.
stop at a shop on the way to work, get back in she starts fine, wont idle immediately but OK to pull away. retarded still for a few more mins then she is fine again like a normal car should do.

a few points that may help you genius' on this site:

a full tank of fuel from the local jet garage gets me around 250 - 270 miles. i only drive weekdays and do 20 miles a day (80% dual carriageway)

occasional thick white smoke, maybe once a fortnight when cold, usually disappears once engine warms up.

i have changed the oil and filter, air filter, fuel filter, plugs.

my father works for a body shop and has access to this snap on computer that plugs into the ecu and diagnoses the car - its awesome, you can start the engine and stuff all from the computer - and it said engine thermal sensor / engine temp sensor and it got replaced, since then we cleared the fault from the diagnostic thingy and NOTHING has changed.

I'm reluctant to go to peugeot garage as I don't fancy getting my pants pulled down over it considering I have access to diagnostic computers all weekend, am I being a tight ar53?

somebody PLEASE help meeeee!!

thanks in anticipation and a huge thanks to the guys running this!!

[desperate to fix my 1.6]

oh forgot she is 2003! thanks again!!