the injector fun begins

[sic_transitgloriamundi]

Well after having my m816 for about two years now i finally have some time to work with it. I just finished earning my college degree at the not so tender age of 33, so now while I sit around waiting for the great job I am suppose to get, I have a little free time to work on my wrecker. I have only had one no start condition in the past and fixed it with the common selector valve replacement and rebuild. This last no start condition instinctively made me believe my injectors where clogged. Long story short the truck was running fine and then the last couple of times I drove it it slowly started to loss power untill after sitting for two month while I finished up my last college course work, it would not start. A shot of either would bring it to life for a second, so I started chasing done the usual problems. First I took a big funnel and c clamped it to the hood above the injection pump and gravity fed clean fuel to the pump, didn't work. Next I took the injection pump off and cleaned the in pump screen, which was completely clogged with a reddish sediment. Reinstalled the pump, but again, no start. I then checked for clogged lines by removing the in between head fuel lines and blowing from front to back and back to front. Both ways I found I had fuel flow. I then removed the fuel line plugs on the last head and primed the pump. I turned the engine over and saw I had good fuel flow out the back of the head. So I went ahead and bit the bullet and pulled the injectors out, which I wasn't really sure if I wanted to dive that far into an engine considering I have never worked on a diesel engine before. Anyway it was not so hard of a job, I didn't have any special injector puller but found a nice size channel locks worked well. One can see from the pictures that my injectors are most definitely clogged, so I am driving a couple hours away this week and taking them to a diesel shop to have a look at whether or not we are going to clean or rebuild. I am also going to go ahead and take the pump and have it done as well. I plan on keeping my wrecker for awhile so I might as well spend the money and redo the fuel system and I bet I will get many years of good service from it. I hope the reinstall of the injectors and valve setting go as well as the disassemble. May need some advice from those who have done this job before about the best way to go about setting the valves and injectors.

 

[Artisan]

Interesting...I wanna watch! Good pics THANX!

 

[73m819]

Have you CHECKED your fuel filter and tank, I would change the filter and then run some sea foam to clean out the system, until you clean the tank, you will have a recurring loss of power/hard starting problem

 

[Jakelc15]

Might as well put bigger nozzles on your injectors while you have them out!

Here is some good reading about setting injectors. Hope it helps you out.
http://www.steelsoldiers.com/showthread.php?73256-Nhc250-valve-injector-overhead-adjusting

 

[sic_transitgloriamundi]

Yeah, my original problem started because I had the drivers tank pulled and welded new steel plates where the bottom straps sat. Anyway while the tank was out I needed to use the truck and switched to the passenger tank which had questionable fuel in it. I knew better, and am now paying the price for it. I am going to have both tanks steamed out. Tried to find somebody to dip them but no one around here that I could find had a large enough dip tank for them. Think I am going to switch to a spin on filter, doubt it will be as big as the original, but should be cheaper and more available. Thought about having the pump turned up to 2250 rpm. Then a bigger fuel button, with larger injectors, but without adding a turbo and air to air cooler and a bigger oil cooler, I am just asking for heat issues. My engine was produce in 88 so I should be able to turn it up, but I think i will keep it set the way it is for now. Maybe in the future if I re-license my truck so I can tow a trailer then I will have to weigh the cost of upgrading my current motor or finding a big cam to start working on a engine swap. Right now I have my truck licensed as permanently mounted equipment which does not allow me to tow anything, at least I don't think it does. The law is vague on the subject. Says i can carry anything that is related to the intended purpose of the truck. All I know is it is the difference between 1500 dollars a year for plates or 180 dollars.

 

[m16ty]

There are other ways to do it but I've always set the injectors with a in/lb torque wrench.