hi again , 52 1.6 cold start problem , this was before the throttle body problem it had . when cold the engine spins over well so its not the battery but doesnt start straight away about 5-10 seconds before it fires up . ecu was reset last week , could this be the coolant sensor faulty on the stat housing , its fine when its warmed up and if it was faulty would it bring a light on , thanks

might not be the same but mine did this on and off for a few weeks before a coil went home.

Could also be cold start solenoid. How does the car run once its warmed up?

Cheers,
Alan

Does it idle and pick up acceleration ok when cold? Should idle at about 900rpm when cold then 750-800rpm when warm.
If the engine temp sensor was way out of resistance then the engine would struggle to start and wouldn't even idle when cold without a battle with the gas pedal

It'll only trigger a warning if it's out of acceptable limits

Is the immobiliser light (padlock icon) out when you start it? Immobiliser will prevent ignition and fuel until it's happy, that can take a few seconds

If you want to, you can follow my Stilo guide to testing your rad fan and engine temp sensor and artifically put it a "cold engine" resistance of 6k for zero C and see if it starts easier from cold then or just measure the resistance the sensor is with engine cold and then hot and look it up on the resistance v temperature chart I supplied there

What is interresting is the temperature sensor of the Stilo vs start brain. When it is nice and hot outside, the car starts after a couple of turns. But when the temperature drops to around 5 degrees C it is hard to start, and takes at least 3 seconds to fire. But again - when temperature drops below -5 C and lower, it fires up faster than my neighbour's diesel (tractor as I call it). Just trigger the key, and "vroooom" 1500 RPM idle. The stilo just doesn't like 2-7 degrees C.

Hey! Only five posts to 1k posts! And that doesn't count the massive spamming me and Stu had back in 2004 at the Leisure Lounge - both being up at night with babies. Kids rock.