Cummins 8.3 ISC Injection Control Valve

[skitches]

Does anyone know how this ICV operates? Does it switch on when you turn the ignition switch on to start or does it come on when cranking. I don't see where its tied into the starting circuit like the old fuel shut off solenoids on the older 8.3 engines. I don't see where the valve has any proportional control. I am thinking the valve operates like the old fuel shut off valve other that it goes thru specific openings to the fuel injector pump and looks like it has return fuel lines back to it to recirculate the fuel back again. It appears to have a magnetic coil to pull it in since I have seen where someone was talking about the Insight software from cummins doing a click test to check the stator. This has to be an on/off voltage going to the stator to trigger the coil.

[Skip426]

The CAPS system pdf I have ( too large to post to the forums ) The system overview , doesn't call the ICV , a fuel shut off ; it describes it as a regulator controlled by the ECM .

BUT; JMHO , if it can regulate fuel flow , I'm sure it can shut it off .

This pdf has 350+ pages ; covers both CAPS and HPCR ;I'll see what I can do to cut it down .

Please take a min to set up a signature line , so all members will know your ISC is in a 2000 Diplomat .

[randomledder]

I’ll take a stab at it but this is from my foggy memory banks. The icv valve controls fuel flow indirectly to the injectors inside that valve there are a couple of pins that are moved by the stator which is driven by the ECM. Think stereo speaker on off signal to make sound but is moving the pins. The driving of these pins causes the fuel to either flow to or dump from the injectors in doing so it can very the timing and flow rate. This is probably an overly simplistic description but should be the general idea. Insite does have an ICV click test. It sends a command to the stator and if it’s working it makes an audible click as the pin bottoms in the housing Sometimes it isn’t the best test in the world as the icv stator can work fine warm then go to poop when it’s hot. The ICV valve can be changed without pulling the pump head if you have reasonable access. It requires a very thorough cleaning but is doable. That’s about all the rambling I have for now.

[jacwjames]

Here is the page right out of the manual.

[Skip426]

Originally Posted by jacwjames

Here is the page right out of the manual.

Jim; that's page 103 of the pdf I have do you have 101 & 102 as individual pdfs ?

I've been trying ( with my limited computer skills ) to cut the document down for posting .

[jacwjames]

Skip426


What I do is determine what pages I want and print them to a new PDF and then just name it appropriately saving it to a location/folder.

I do this all the time when I'm working on something and want to capture it for future use. This will even work on schematics that I zoom in on, I just print current view then name it name it for the view.



More the one way to skin a cat.

[skitches]

Thanks Jim, just read thru your post. I just finished getting all the wires documented as far as which ones are positive and negative so when I hook the ICV back to the ecm it won't fry anything. I did hook up a meter to see what the voltage was coming out of pins 6 and 7 that go to the ICV. I got roughly 5 volts coming out of the ecm so it makes since the ICV is controlled with voltage for the regulation. I didn't want to remove the ecm connector thinking of bending a pin or pulling a wire out so I just measured the voltage of the 2 wires that originally went to the ICV from the ECM, I knew this because there were only 4 wires broken and I checked continuity on the Transitor Suppressor by cutting one of the wires because it was easy to get to and butt splice back. I will hopefully get the wrap back on the wires and taped up and connected tomorrow and hopefully it will be back on the road. I cannot imagine anything else keeping it from running other than the broken wires going to the ICV and Transitor Suppressor.

[skitches]

How do you access the back screws if you don't pull the accumulator above it. Also, I believe I saw where you had to get the engine on top dead center of #1 of which I don't understand if you are not pulling the pump, only the accumulator.

[Ray,IN]

In 2020 my fuel distributor module failed. When it fails there is no way the engine will run.
Cummins Great Plains replaced the fuel distributor and transient suppressor and it has ran great ever since. ($5K)
The fuel distributor runs off 12V, what caused mine to fail was the Transient Suppressor failed first, that in turn allowed a voltage spike in the distributor motor, which then fried the motor.

[Skip426]

Originally Posted by jacwjames

Skip426
What I do is determine what pages I want and print them to a new PDF and then just name it appropriately saving it to a location/folder.
I do this all the time when I'm working on something and want to capture it for future use. This will even work on schematics that I zoom in on, I just print current view then name it name it for the view.

More the one way to skin a cat.

And the cat isn't happy about any of them .

Thanks Jim , Windows 11 ( the cat in this case ) doesn't want to co-operate with anything I've tried so far , so I'll give that a try .

[randomledder]

Originally Posted by skitches

How do you access the back screws if you don't pull the accumulator above it. Also, I believe I saw where you had to get the engine on top dead center of #1 of which I don't understand if you are not pulling the pump, only the accumulator.

You can get the back bolts out just by backing them out with a 8mm wrench they aren’t long enough to hit the under of the accumulator then just slide it out. I think the rate shape tube has to come off to slide it out if memory serves correct. No need to move the engine to TDC for a ICV repair.

[skitches]

I thought you had to remove the 4 screws that are in the stator. Are you talking about removing the entire valve and not just the stator? Guess I was confused. LOL

Also, are the 8 mm screws the 4 bolts that goes thru the accumulator located on top?

[randomledder]

By apologies. Yes I was talking about removing the entire ICV valve.

[jacwjames]

I found this video that shows how the CAPS pump is assembled. It might help you visualize what needs to be done.

https://www.youtube.com/watch?v=rzT43yjPbNI