Have you checked the hoses for air leaks?
Fuel + air + compression

 

Are you getting fuel to the injectors?

If not, are you getting 12V to your FSS spade?

If yes, how much is coming out? A lot or a drop?

If a lot, then what's your voltage on the batteries with the key off? Have your batteries checked. I had a new battery once with a bad cell and it would turn over but never start. Even with a jump, that bad cell would keep it from starting.

If a drop or no fuel at the injectors, then it could be a stuck metering valve. If you are more handy than the average bear, then you could try fiddling the valve, but it's not for the amateur mechanic:


If you have still done all this and it still doesn't start, then I'd suspect timing is off. Do you have a timing gun and ferret meter? What is your IDI timing after you changed the IP? When you took the IP off, did you leave the gearhousing on, or did you take off the IP gear with the IP?

If you took off the IP gear with the housing and IP, then you probably skipped a tooth and ruined the timing. You'll need to pull the front plate off and re-time the gears.

 

Ok, I am going to make some assumptions here about the condition of the truck.
1) You checked the glow plugs and they now test good via a test light or volt meter.
2) You show good function from the glow plug controller and the glow plugs do cycle.
3) You are getting fuel to the injectors, since you stated you have bled them.

So if the above is correct, and you are getting fuel delivered to the cylinders, with new injectors, new lines and Ts (I am assuming), new glow plug system. Then the only thing left is timing or a failure in the engine that is not repairable easily (example: burned through pistons or blown rings). So I would ask, when cranking, does the truck smoke? When you cycle your glow plugs does the Wait to start or Glow Plugs light turn on for about 12 seconds and then shut off? Have you attempted to disable the glow plug system and start the engine with a small (very small) spray of ether to test the engine for function? These questions will get us to where we need to be.

 

ive had mine with broke rods still run so it would have to be much more serious

 

When cranking if you don't see smoke your not getting any fuel, also when bleeding the injectors don't tighten them all the way until they are actually squirting out fuel to the point it sprays of stuff, i get em barely snug, they will start to dribble but you need to keep cranking until they actually squirt.

If your getting fuel to the injectors and its a good squirt but it still won't start you could unplug the glow plugs and give er just a sniff of ether and say half pedal when you crank and even with low compression it should try to start. Just don't give it too much ether or it'll vapor lock and you'll have to drag start it (hopefully you have a standard) It takes quite a bit to vapor lock it though, just a puff down the air cleaner is all it takes.

Once it at least halfway runs you can diagnose how good and if it's erratic and surges then you have air getting in somewhere.

 

Also, make sure you don't crank the engine to death. If you crank it for 10-12 seconds then give it at least a minute to cool down. The starters are a weak link in our trucks.

 

 

 

Could be a wore starter, these engines need to spin so fast or they simply WILL NOT START

If you have a volt meter you can check what the battery voltage drops to when cranking, it if drops below eleven or so and the batteries are good you have a bad starter most likely

A lot of times though, you can take that starter apart on a bench, clean it out with diesel and a wire brush, sand the brushes and contact points with fine sand paper and she will keep going for along time. Just wash the diesel off with water and grease the ends of the shaft lightly.

If it really spins fast enough but doesn't do anything with ether your still not getting fuel, it takes a lot of ether for theses trucks to run, without fuel spraying in the cylinder mine won't start no matter how much I give it, unless I wanted to take things into the danger zone. So I bleed it a little more til a sniff does the trick. Sometimes it takes a while especially with a weak starter

 

What is the condition of your battery cables? You could have a healthy starter and good batteries but worn or corroded cables could keep your truck from starting. Given the state of the wiring harness of my truck I'm inclined to believe that engineers were either just really lazy "in the day" or didn't give a darn.

 

Ever had one apart? These Mitsubishi and Denso starters have HUGE long lasting bearings for their size and are high quality throughout. I put 230,000 miles on mine before an overhaul and then the only component that was really worn out were brushes which is to be expected after so many years. The only crappy starters with a premature failure rate were the Delco starters that IDI's came with for the first one or two years the engines were first produced back in '83 or '84.

 

Ok smoke on exhaust means it is delivering fuel, then with the Ether you did not get any kind of firing? I am going to assume it must be timing or a weak starter. They need to spin pretty fast to get it to start. The starter should wind it up to almost operating speed. They need that speed of rotation to create the proper compression before the gasses escape through various passages in the piston rings. I might check the starter and see if it is either, A) not connected or corroded connections, or B simply defective and needs replaced. Timing is the last check here, if the starter is good then it has to be so far out of time that it is injecting fuel after or at the very end of the power stroke. But check starter first.