The problem is when starting it will not start. It will always start after three to four tries with white smoke coming from the exhaust for few seconds.. I have changed fuel filter. All fuel lines have been chage four months ago. Turbo changed 5 months ago.

 

Have you checked out the glow plug system? Sounds like you may have a bad GPR.

GPR operation - YouTube

Glow Plug Testing - YouTube

 

I'm with Ken on this. But also how does it start after It's been plugged in for a couple of hours?

 

GPR checked ok as in Woodnthings video. I plugged in heater even its 69 degrees outside.
IT starts right up. All in the world do you unplug the two crazy harness to check glow plugs.

 

GPR checked ok. How in the world do you unplug the harness to check glow plugs.
I did plug in heater for a little bit, even though outside temp is 70. It started right up.

 

You may have to remove your CAC (Intercooler) pipes to get to the plugs. It's a tight fit.

Sounds like that since it starts right up due to the truck being plugged in (keeping the engine "warm"), you probably just need to replace all of your glow plugs. They are about $11 each, and MAKE SURE you get the Motorcraft OEM plugs and not Autolites or another aftermarket. This is one of the items that it truly best to get OEM parts. The job will probably take you 4-6 hours, depending on your experience with removing the valve covers.

It's not complicated job, just time consuming, and you need to have a few versions of sockets (short, long, swivel) to make it "easier." The back bolts on the driver and passenger's side valve covers are tough, and so are the two lower back bolts on the passenger side valve cover as it's up against the A/C evaporator wall. Heck, I helped with one-and-a-half trucks yesterday on this very thing at the Houston GTG, so it's not too tough.

Oh, and you'll want a 5 inch (approx) length of 3/8" heater hose to help finish unscrewing and pulling the glow plugs out. This is simply due to not being able to fully unscrew the glow plug with it on the socket...the socket gets stuck as it's a hair too wide.

 

What is the other relay in front of the gpr.

 

Intake air heater relay

 

It does nothing for starting. It helps to clear the smoke AFTER starting on a cold day when the conditions are right for it to energize.