Alright everyone Albert sent me his datalog and got to look at it.. I noticed his fuel trims were not switching and they were constant positive number.
![Albert.JPG Albert.JPG](http://www.wickedstangs.com/data/attachments/2/2984-6a7a53a5b572a3d420426a48ca2cdd93.jpg)
Consistent Positive or Negative Fuel Trims
If the engine starts poorly when cold and the STFTs show a positive trim at idle, suspect the fuel pressure regulator is failing to maintain a proper fuel rail pressure. In this case not enough petrol is being injected into the inlet to provide a good combustion - the engine will often struggle to start and the STFT will continue to swing to positive trims at idle.
He has replaced it and he sent me a new data-log file and it looks much better... Fingers crossed he will be checking it out in the morning...
![Albert.JPG Albert.JPG](http://www.wickedstangs.com/data/attachments/2/2984-6a7a53a5b572a3d420426a48ca2cdd93.jpg)
Consistent Positive or Negative Fuel Trims
If the engine starts poorly when cold and the STFTs show a positive trim at idle, suspect the fuel pressure regulator is failing to maintain a proper fuel rail pressure. In this case not enough petrol is being injected into the inlet to provide a good combustion - the engine will often struggle to start and the STFT will continue to swing to positive trims at idle.
He has replaced it and he sent me a new data-log file and it looks much better... Fingers crossed he will be checking it out in the morning...