Hello, do you know if there are any codes in the computer? What you are describing could be either a high pressure oil system leak or a failing FICM. It would be very helpful to know if there are codes stored. Thanks

Is it harder to start whenthe engine temperature is colder or warmer? How is the performance affected by engine temperature, better or worse as the engine warms up?

After it warms up the power and starting are good?

With the symptoms, it is had to say whether it is the FICM or a leak inthe high pressure oil system. Normally if the FICM is failing, it is very hard to start cold, but runs fine when warm, until it just about to fail. How long has this been going on? A leak in the high pressure oil system will make it hard to start and lower power when hot. This can also cause it to have to sit untill cooled slightly before restarting. I think you may have a leak in the oil system from your last comment. When it starts cold, does it run very rough?

OIl pump for the engine or for the injectors?

OK, then you will need a scan tool to read the codes and monitor the sensor data. I believe that there is a leak in the high pressure oil system. This is not something you want to just go into without a reason to. We will need this in order to continue. I don't want to tell you to change something without codes or sensor data to verify it. Guessing will not save you money in the long run.

You just reply back to me like you are doing now. Thanks