Look on the page for the fuel filter, relief valve is usually on fuel filter mount. 
Have you checked your fuel pressure?
Bob

bluox wrote:

A picture would sure help as your description needs more information.
If by chance you are looking at the cold end of the turbo those joints are usually sealed with a couple of yellow O-rings that allows for some misalignment.
If you are looking at the hot end those joints are sealed with metal piston type rings.
Bob

Bob, please see the picture below. This is where the cold side of the turbo tubing meets the head. They fashioned an adapter to full this gap but there is still a small gap as seen in the picture. I cleaned up this area the best I could yesterday and put some RTV in the cracks. I am going back today and run it and see if performance improves any.

 

That is truly a cobbled-up mess.
What is that bracket with empty bolt holes in the top of your picture?
If you are going to use this tractor you will have to fix this mess.
Good luck
Bob

bluox wrote:

That is truly a cobbled-up mess.
What is that bracket with empty bolt holes in the top of your picture?
If you are going to use this tractor you will have to fix this mess.
Good luck
Bob

Bob, I completely agree. She is a hot mess. I'm trying to dig my way out. When they dropped in a 3306 I think they had to cobble together different turbo inlet tubes to make it fit. I actually got the gap filled up nicely with some RTV and its holding very well. However, its still running the same. It sounds good but it pops occasionally and has some white smoke. I put some stanadyne in the filter today and let it run a while. I also put some in the tank. I found the pressure relief valve on the filter body and will try to get that off and inspected tomorrow. I have already put new injectors in it and I've got new fuel lines ready to install. I plan to keep chipping away at it until I can get it running a better. Then, I am going to tackle a brake job.

bluox wrote:

Look on the page for the fuel filter, relief valve is usually on fuel filter mount. 
Have you checked your fuel pressure?
Bob

I checked fuel pressure today at the filter housing and it looks to be at 35 psi.

 

Your fuel pressure is fine.
you don't need to monkey with the relief valve.
Bob

bluox wrote:

Your fuel pressure is fine.
you don't need to monkey with the relief valve.
Bob

Thanks Bob. Where should I be looking next to try to find the occasional popping and white smoke? I can take a video if that would help.

I went ahead and pulled the plunger assembly on the fuel filter housing today to inspect it. Please see pictures below. The plunger appears to be either chipped or worn away on one side. Could this possibly explain some of the popping and white smoke? I have a replacement ordered.

 

I guess we will see.
I kind of dough it.
I've never seen one worn like that ,is the spring broke?
Did you buy the whole valve or just the plunger?
Bob

bluox wrote:

I guess we will see.
I kind of dough it.
I've never seen one worn like that ,is the spring broke?
Did you buy the whole valve or just the plunger?
Bob

Here are the parts laid out in the way they came out. The spring seems fine. I cleaned up the fitting to the far left and it seems fine. The "stop" is in between the fitting and spring and it seems fine as well. The only other part is the plunger to the far right. This is the only part that had an issue and it's the only part I ordered. I'm open to feedback if you think I should replace some of the other parts. The diagram from the parts manual is shown in the top right of the picture but it doesn't do a good job of illustrating the parts.