Cold start problems

[hammersfan12]

Sometimes on a cold/hot or day/night , the engine runs lumpy but as soon as I start driving it's fine, it seems to be only since I put a k&n filter in could of it already screwed with the air flow meter, and things like that. I have replaced the temp sensor as well.

Thanks

Charlie

[Brianmoooore]

My first suspect would be an injector leaking fuel into the inlet manifold when the engine is off. This will give a rich mixture when the engine starts, which will sort itself when the fuel has all evaporated.

[hammersfan12]

Thanks, would it be new injector or just the sill. Also would it make the car slower.

[Brianmoooore]

Injectors can be rebuilt for £10 a time, and in general terms will be the most return in MPG and BHP per £ that you will ever get for your car, if they are more than 50,000 miles old.
See 'Injectortune' in our traders' forum.
To test for a leaking injector (and a couple of other faults), you need to connect a pressure gauge to the fuel rail and see what happens to the fuel pressure after the engine is stopped.

[hammersfan12]

Thanks, and yeah there 183k lol

[hammersfan12]

And I'll have a look at the injector rebuilding