Help nissan 720 sd22 diesel

[waynosworld]

There are lots of reasons to do that, one of the diesel components quit working and it would not shut the engine down anymore is one and that is an easy fix to not have to lift the hood and shut it down, or maybe it would not start because the arm would not move to the start position either, a low battery can cause the same issues that I just recently found out myself on my 720 diesel.

In the past I had people calling me about why their diesel would not shut down when they turned the key off, it was stuck in the run mode, I was always telling them to cycle the connection unplug and plug back in the injection pump controller plug, it appears they lose connection from dirt, corrosion, they would drive all the way to my house to have me cycle that plug and have everything work fine, I use spray electrical cleaner and blow it clean with compressed air myself.

Even that arm he removed can cause issues with starting and shutting the engine down if it is not adjusted properly.

[Raptor6717]

OK, I'm learning. I discovered that the truck came factory with an sd25 diesel. The old man swapped the engine to an sd22 because the sd25 blew up. He rigged his own glow plug system, which wasn't working properly and added a manual shut off. The reason it wasn't starting was because the injection controller motor was never hooked back up and the pump was always in the run position. The problem is, I think he swapped the sd25 controller onto the sd22, and the rod is not long enough to reach it. That is why it was never put back on. (This is all my theory of what happened to the truck.)

So, am I missing something, like another piece at the end of the rod that connects to the injection pump controller? Or is it the sd25 controller and the sd22 rod is not long enough?


Another thing. It is now running rough again. I heard the rod knock noise that the man was talking about. It sounds like the injector is dumping fuel into the cylinder and it is blowing white smoke and missing.

It does start immediately now that I am giving it more fuel manually.

I opened the diaphragm housing and it has a tear in the outside part, but the truck still runs.

IMG_2899.jpeg (114.39 KiB) Viewed 156 times

IMG_2898.jpeg (116.39 KiB) Viewed 156 times

[plenzen]

Not too sure about the shut down lever and perhaps Wayne can offer some ideas. Mine had an electric shut down on the VE pump.


I would agree with your thoughts about a leaky injector(s). That "rod knock" that you hear is likely ignition pre detonation causing that sound.
Simply too much fuel and that cylinder(s) is firing too soon. Like having the timing advanced too much.
It may be time to remove injectors and have them rebuilt.
A bit spendy but I doubt that any "additive" ( Stanadyne, Power Service, Red Line etc) will work.
You could try them at double doses.
The introduction of the ULSD years ago contributed to this problem.
After rebuild, if you decide to go that route and rebuild them, one of the above mentioned additives might be a good idea per fill up.
I know on the VE pump I had it was pretty much a requirement. As previously mentioned they were a bit more sensitive to that kind of thing as they used the fuel to lubricate them rather than the engine oil like the inline pumps use.
Your injectors still require the fuel to lubricate them and the "old school" injectors were not built for the ULSD of today.
IF you decide to go that route and remove them there are a few gaskets you will need to source first.
If you search the forum you will find pictures of the ones you will need.
Digging the copper "tip" gaskets out of the head can be a bit of a challenge IIRC. I did not have the issue on my SD25 as they had a different style of tip gasket than the copper "crush" type.
The leaky injectors can also contribute to your "difficult" starting as well.
Removing the injectors is not a difficult job in itself, but, as previously stated, getting the tip gaskets out can apparently cause a swear jar to fill rapidly.

[Raptor6717]

OK, I'm learning. I discovered that the truck came factory with an sd25 diesel. The old man swapped the engine to an sd22 because the sd25 blew up. He rigged his own glow plug system, which wasn't working properly and added a manual shut off. The reason it wasn't starting was because the injection controller motor was never hooked back up and the pump was always in the run position. The problem is, I think he swapped the sd25 controller onto the sd22, and the rod is not long enough to reach it. That is why it was never put back on. (This is all my theory of what happened to the truck.)

So, am I missing something, like another piece at the end of the rod that connects to the injection pump controller? Or is it the sd25 controller and the sd22 rod is not long enough?


Another thing. It is now running rough again. I heard the rod knock noise that the man was talking about. It sounds like the injector is dumping fuel into the cylinder and it is blowing white smoke and missing.

It does start immediately now that I am giving it more fuel manually.

I opened the diaphragm housing and it has a tear in the outside part, but the truck still runs.

[Raptor6717]

Any thoughts wayno?

[waynosworld]

A compromised diaphragm can be a big issue, the engine can try to run away(rev uncontrollably), this is not good, my 720 diesel truck did that once to me but I could not figure out why, it never has done that again since and that was years ago, maybe the throttle got stuck and has never did that again, I was standing on the brakes slowing it down and things got better.

As for the rods, I have seen/own rods that do not work as they appear to be too long or too short, one of the symptoms for me has been the engine will not shut off or it will not start, the arm on the injection pump is adjustable, but keep in mind that even the smallest adjustment can cause the same issues, it will not start or it will not shut down, I just went thru this issue, my fusible link was not making good contact, the battery was not charging properly and the battery got low, all of a sudden it would not start, I had to remove the arm to start the engine, this was new, by that time the battery had only a couple more starts before the starter would not turn the engine over, I charged it, but before that happened I had adjusted the injection pump arm so it would start, it would not shut off after that adjustment.

So, like I said I charged the battery, since that time I had to start dealing with it either not starting or not shutting down, I noticed my lower arm connection was kind of loose, it turned out the plastic bushing had worn out and half of it had worn thru, I had extra injection pump controllers so I got a plastic bushing from one of them and fixed that issue, I then started adjusting the arm(two screws and a slot), I adjusted them until I finally found the sweet spot, it starts fine and shuts down, but it shuts down slightly slower and it shakes the engine/truck a little, there is likely a spot where it shuts down smoother but it shuts down so I called it good.

OK, that said a fully charged battery is needed for things to work properly, it has to turn over fast enough to get the controller to move to the start/run position, it also has to shut down when the key is turned off, finding that spot can be frustrating, it had me talking to myself, the Phillips head screws are very small and almost worthless now, I need to find new screws.

I cannot say much about the knocking as I am not there to hear it, I had to change out the o-rings in my injection pump connections where the injection pump lines go from the injection pump to the injectors, at some point doing this some dirt appears to have gotten in the fittings on the top of the injection pump, in the lines going to the injectors, this caused a bad knock, while it was running I bled all the connections, to me it appeared the dirt had made it to the #4 injector, I kept opening and closing the fitting on the #4 injector and maybe it was the surging but the injector cleared and it quit knocking, then I could hear all sorts of other noise, I finally figured out and fixed all the noises and hoped this was the end of this ordeal, so far no more issues and my alternator is charging better than I have seen it charge in a long time.

OK, I am slightly worried about mentioning this, when I remove the rod to get the engine started because of issues I do not know of yet, when I re-install the arm back onto the injection pump arm, I have to move the injection pump arm towards the firewall(shut down position), if the arm is too short or long the injection pump controller will start squealing because it cannot move where it needs to move, this can ruin the injection pump controller, like I said the injection pump arm is adjustable, but if you loosen them screws you have to find the sweet spot which was a major pain to me, I likely spent a couple hours figuring that part out, either it would not start or not shut down, that had me talking to myself also.

I do not know how you are manually giving the engine more fuel, the only way I know of doing this is to hold the injection pump arm to the start position, that would take two people to do, one holding the arm to the start position while the other turns the key.