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 20 times

IMG_2898.jpeg (116.39 KiB) Viewed 20 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.