That issue, youre right in solution and cause, but its only if the car fails to start at all. Craig said that it starts but when he puts his foot down it gives up a bit Craig do the fuel filter I reckon. Mines always done it (being manual choke) I think the lambda sensor is also a good idea, your ECU may be starving your initial combustion of fuel*. Sorry, uni's taking over lol... Do fuel filter as its cheapish, then lambda, then get back to us *Going on the idea of, the petrol is colder, so its more dense. Meaning, your sensor cant differentiate between cold and warm petrol, so when it senses the denser petrol, it thinks theres just more of it, and increases air intake, hence making it lean burn.