Thought I'd do a sticky. This is for the Mechanically injected 6.2 and 6.5TD's. Although there are many similarities to a DS4 used on the later 6.5s there are differences. So here goes.

I have done many many 6.2 IPs so I got it down to about just under 2 hrs if the new IP is sitting next to me ready to go on. today was not a 2hr day...
So the symptoms were hard starting if the truck sat, low power lot's of smoke under any kind of acceleration and fuel around the throttle shaft. yep, she was done. So I got a reman from a guy I know who does them on the side....Guess he had a bad day. The reman IP was a dud and I needed the truck back asap so I ripped i back out and put a used one on I had from something else. it runs mint now. a DB2-2829 4544 is the preferred IP for a J code but in reality any 6.2 DB2 will work just fine. The used one I put on was a 4875 off a 90 V2500 Burb.
So the pics are pretty self explanatory but I'll try to do posts explaining each step. This will probably take me a few nights. I have lots of pics.

 

First step, get the tools ready. Also take note of the double nuts on the air cleaner. I strongly suggest doing this. Here's what can happen if you don't..The studs break from vibration at the base and then flop around and eventually work loose from the wing nuts and the guess where they end up ??? I was pretty pissed having to toss a perfectly good 6.2 in my 83 after it made it's way into the cylinder and destroyed the head, piston and cracked the cyl wall. Also I like a few shots of the motor before I take it apart in case I get Alzheimers mid project...

 

Next step is to remove the intake. I strongly suggest taking an air blow gun and blowing compressed air all around the intake flages and try to blow away any losse crap that might fall into the head when the intake is lifted off. Then next step is to remove the CDR(That tuna can looking thing). Mine was full of oil and probably original so that is on the replace list. The little stupid clamps that hold the hoses on can be pried apart carefully with a flatblade but they do tend to break so don't worry if that happens . A regular hoseclamp will be fine to replace it. The two nuts for the CDR bracket to valve cover will probably try to turn the whole stud and twist the bracket so have some channel locks handy to hold the bracket from twisting. Same goes for the stud holding the grounds. Expect that whole stud to twist rather than the nut come off. BTW now is a good time to clean those grounds upon reassembly. To get the bottom half of Inj line holders off you can pry the lines up VERY GENTLY the slip it out. The intake will not come off without removing them and they will bend if you force them.Also take note of which bolts go where on the intake as some matter. Others do not.

 

You can see better here what was wrong with mine. If you see wet around the IP the seals are shot and this can cause air in the fuel as well as drainback and hard starting.

 

Next it's time to remove the lines. DO NOT BEND THEM. They have a coating on the inside that can come loose. They come off in pairs of two. Make sure you mark where they go. It can be a bitch later if you don't. Also I recommend plugging the injs. I have plastic plugs specifically made for his I acquired over the years. You can buy these or make them. Saran wrap and zip ties work as well as tin foil too. If you get any debris in the nozzles, your screwed. Clean clean clean. The vacuum line for the trans is in the way on the pass side. I cut mine out of the way as my truck no longer needs it. I did not plug the holes on the IP as it's junk IMO.

 

Now you take off the three bolt holding the IP shaft to the cam gear. These three bolts are accessed through the oil fill so that mus be removed. Again, clean the area first with a blow gun. Now you will have to bar the motor over. It is not a good idea to tap the key to do this. I have heard stories of it shearing the keyway on hte camgear even though it has never happended to me so do that at your own risk. Let me make this clear ...It is NOT necessary to remove the timing case cover. Just try not to drop the gear bolts into the timing case but if you do ..DON"T panic. It's near impossible for them to fall past the gear so a small magnet will easily retrieve them. I dropped one today.Once the three bolts are removed then remove the 3 bolts that hold the IP to the timing case cover. I didn't go into detail about removing the throttle cable or throttle cable bracket. if you can't figure that part out, you probably should not be doing this job...

I threw in an extra pic of another DB2 on my bench with the cam gear so you get a better idea but you will not see the gear during this job as you access the bolts through the oil fill.

Also you should put some shop paper towels in the ports in the head. JUST DON"T FORGET THEM...

 

OK now we are ready to install the reman. A few notes. Don't forget to swap over the follower(shown) Also the 3 camgear bolts should be thoroughly cleaned and coated with blue loctite. You'll notice the IP shaft has an alignment pin. It is possible to accidentally put the alingment pin in a bolt hole. If this happens none of the bolt holes on hte cam gear will line up with the threaded holes on the IP shaft so watch for that. My advice is to put the old one next to the new one and line them up the same. Replace the gasket on the timing case cover for the IP if you have a new one. if you don't and the old one is in good shape, use it over. DO NOT USE SEALER !! The gasket is made to seal without it and sealer will cause issues as the IP is meant to be moved around during time set. Generally the marks should line up but I have yet to see one run good with the marks aligned. I usually start with the IP bumped about a matchbook cover to the drivers side from the mark on the timing case cover. I usually put the 3 nuts on but a little loose then do the three bolts for the cam gear. I make the first cam gear bolt snug then tighten the second and third and then retighten the first . If you crank down on the first one you could **** the gear and crack it.

 

OK so once the IP is bolted back up it's time to re install the lines The bottom two nuts on the IP are a PIA to tighten I strongly recommend a 5/8 flare crow foot on a wobble drive extension. It works perfectly. A regular flare on the rest. I usually get them all started and hand snugged to the IP first then hand tighten the nuts on the nozzles. Leave these nuts a little less than hand tight. Make sure the pump is positioned where you want it to be before tightening the lines on the IP side. They have enough give to move the IP a little each way but it's always best to have as little tension on them as possible. Don't be afriad to use a little Ummph on the line nuts at the IP. They must be tight. Leave the nuts at the Injs loose for now. They will be tightened after purging. Put everything on in reverse order but take note of any issues that need to be addressed. I had a coolant leak by the block off plate on the RR head. Also clean the grounds good while they are off. I like to reassemble them with Copper Antiseize. Don't use any sealer on the intake gaskets . It is not needed nor recommended. Don't forget to remove any rags you may have used in the heads. I used an air grinder with gasket discs to clean everything up. If you still have factory intake gaskets they will be stuck and a bitch to remove. I also recommend using a face mask if using a disc grinder as the dust could be asbestos. Torque specs are in the Manuals. I don't have one in front of me right now. Reconnect the fuel line to IP before putting intake on. Hopefully you have an electric LP. If not purging will be a PIA and make sure you have two really good fully charged batts and have a charger on standby. I would recommended changing the fuel filter at this time as well.
Now once you put it all back together it's time to crank it up. What I recommended it cranking the engine with your foot to the floor until you see fuel at the inj nozzles(remember we DID NOT tighten those nuts yet). ONce you see fuel there stop and tighten all the nuts. Now cycle the glows and foot to the floor and crank until it starts. It should not take too lng but don;t over heat the starter. You may have to take a break. Mech LP's are more of a PIA. In fact I would purge the fuel filter first with a hand vac pump. A 24v starter is bucks. DO NOT DO NOT DO NOT !!! USE ETHER !!!! No Starting fluid ever!!!!. If it won't star after a few attempts, then troubleshoot why. NO ETHER !!!!! Mine took about 45 seconds to start. Once it fires keep it at half or better throttle for about a minute to purge remaining air. now at idle inspect for leaks at the lines etc.

 

Now...that the job has been documented...The truck ran like crap. It would stall if I goosed it and if I tried to hold the throttle at 2000 rpm it was surging like mad. No air in the system and 10 psi of fuel pressure. So I condemned the new IP as a bad metering valve and or governer. It was now 4;30 and just getting dusk. It had 4.5 hrs in it but that included draining the cooling system to fix a coolant leak running to auto parts for fresh coolant etc. I had another DB2 used from a burb I had but was originally hesitant to use it which was why I opted for a reman so I would not have to do the job twice...So I ripped the bitch back apart and swapped in the used pump in just under 2 hrs. I started it with the intake off in case this IP was a dud too. Truck ran beautiful. OK I bolt the intake back on start finishing up and my son comes walking over and says Daddy don't yu need this ? !@#$%^(see pic)
Vid of the truck with dud IP and then used one.

 

Yep the follower pin. F!@K. Now I was determined. it was dark. I ripped the IP back out a third time and put that in. 1.3 hrs flat. This time I left the front set of IP lines on, the fuel line on and the throttle linkage on. I don't normally like to leave the lines on but since I did not loosen them on the IP they were still clocked right