[Rob. Smith]

2 litres of crook fuel in 20 litres of new fuel wouldn't affect the starting of the engine. You've flushed the system...It should be OK. Try some "Start ya bastard" in the air cleaner duct.[ its an Ether based product by Nulon ] If it fires then you can look at dirty/ gummy injectors. Put some injector cleaner in the tank and you might be right. I'm no expert but I've seen this happen before.