1.4i doesn't always start without pressing accelerator.

I have a C3 2006 (facelift) 1.4i. When i come to start the car it doesn't always start and if i try again it still doesn't start, however if i press the accelerator the second i turn the key it'll start.
Also when the car is started it runs smooth.

Hi ssnow66431

Also when the car is started it runs smooth.

You answered my first thought already. I thought about a faulty accelerator pedal

I would start by pulling out the codes and investigating with the Lexia tool. OBD tool won't give enough information. With the lexia you can delve much deeper into the system and see what the sensors and immobiliser are up to and see the readings as you turn the engine over.

Tips for reading the codes are;
1. read the codes, make a note of them (screen capture with alt+prt screen and paste into new image)
2. delete the codes (that are not permanent)
3. investigate and fix the permanent faults
4. start the car and then re-read the latest codes and investigate those.

I had the same problem, it was fixed by changing the spark plugs, cleaning the injectors and cleaning the petrol admission system.

Mine was like this, after a bit of a faff around, I end up changing:

Spark Plugs
Oil (Service Due)
Coolant (service Due)
Engine Flushed (Before Oil Change)
Oil Filter, Air Filter, Cabin Filter

Ran 1/2 bottle of Redex Pretrol injector cleaner through it with half petrol + fiver petrol to swish it around, ran the car and smashed it out on some back roads, now it starts pretty much 100% of the time, it was only doing it when It had just been turned off, which indicated a fuel injector problem, I know they're dirty, probs on their way out, but this helped, and now I just run half a bottle every 1K miles using this method, it seems to be running fine, and unlike some of the other products, it doesnt destroy the injector or fuel system, as it's main job is to just destroy any deposits in the injectors.