Isuzu stop solenoid wiring question

[John V]

Hello, I have an IHI 55j2 with an Isuzu 4jb1 engine in it. I'm trying to figure out the proper stop solenoid setup for the machine as I purchased the machine with many missing parts. I bought one of these solenoids off ebay:

It has three wires, and there is a linkage that connects it to the injection pump to stop it. The solenoid pulls in to shut off fuel.

The wiring diagram (attached) for my machine shows the one lead going to ground, one going to B terminal on the ignition switch, and one going to BR terminal on the ignition switch. The only way I managed to get the solenoid to do anything interesting was to connect the blue wire to B, red to BR, black to ground. When BR is 12V, the solenoid would extend. When BR was 0V it would retract. Seems good... except the solenoid was getting extremely hot, and now appears to not be working at all. Not sure if I've wired it incorrectly, or purchased the wrong kind of solenoid? Any insight would be helpful.

 

[uffex]

Good day
I guess what you have is a pull and hold solenoid, key operate high current to pull, a low current power remains to hold the solenoid in the set position. Turning the key to crank you get power down two line's return the key to the run position only one cable remains live (Hold).
Hope it is of help.
Kind regards
Uffex

 

[007]

Without displaying the information you received with the solenoid I cannot tell what you bought.
Old machines had solenoids which had a pull in coil and a hold coil.
Your machine was fitted with a more modern style which are electronic and if you start powering the wires around the wrong way you will probably stuff it.
It had a ground wire and a battery wire which stays permanently powered B terminal.
It had an ignition wire (Connected to BR).
The solenoid does nothing when you energize the B wire and does nothing when you energize the BR wire but when you remove power from the BR wire the solenoid will pull in stopping the engine and after a short period relax again.
Its up to you to identify your new solenoids wires.
Regards

 

[John V]

Good day
I guess what you have is a pull and hold solenoid, key operate high current to pull, a low current power remains to hold the solenoid in the set position. Turning the key to crank you get power down two line's return the key to the run position only one cable remains live (Hold).
Hope it is of help.
Kind regards
Uffex

Interesting. I'm wondering if the wiring diagram has a slight inaccuracy. Looks like it has the pull lead going to BR, which is always hot except for OFF. Since the pull solenoid pulls a lot of amps, it would make sense that it was getting very hot since it was always on.

 

[John V]

Without displaying the information you received with the solenoid I cannot tell what you bought.
Old machines had solenoids which had a pull in coil and a hold coil.
Your machine was fitted with a more modern style which are electronic and if you start powering the wires around the wrong way you will probably stuff it.
It had a ground wire and a battery wire which stays permanently powered B terminal.
It had an ignition wire (Connected to BR).
The solenoid does nothing when you energize the B wire and does nothing when you energize the BR wire but when you remove power from the BR wire the solenoid will pull in stopping the engine and after a short period relax again.
Its up to you to identify your new solenoids wires.
Regards

Yes, this is how the solenoid was acting. I can't find the documentation that came with the solenoid unfortunately. Attached is a pic of the setup. Tried calling Isuzu but they referred me back to IHI. The 4JA1 that was originally in this machine has the same setup for the shutoff, but I have no idea what the actual solenoid originally looked like as it was pulled off the machine prior.

 

[HeavyTech]

Easy solution go buy a new oem from your local dealer

 

[007]

Easy to tell the difference.
One solenoid had to be pulled in for the engine to run and relax to stop and the other has the solenoid pull in to stop the engine and relaxed when the engine is running.

 

[HeavyTech]

Easy to tell the difference.
One solenoid had to be pulled in for the engine to run and relax to stop and the other has the solenoid pull in to stop the engine and relaxed when the engine is running.

The dealer knows based off model serial number

 

[John V]

We will see. Isuzu dealer doesn't know based on engine s/n. IHI parts manual doesn't have a p/n for the stop solenoid. Hopefully the IHI dealer can do some digging and find out for sure.

 

[HeavyTech]

On the top of the valve cover on the engine there should be a id plate / sticker or sometimes both

Call the engine manufacturer directly with your enquiry to the part number, once you get the part number you can contact your local dealer to order or perhaps they have in stock

That is what I would do

Serial number: Should be stamped into the casting on the side of the engine block

Engine model, family, serial

 

[willie59]

The question I have, how many harness wires do you have where the harness connected to the original solenoid? 2 or 3? You have to get a solenoid that will work with that. And you can't use a 3 wire solenoid if you only have 2 wires, unless you wish to do "why would you do that" modifications. Aside from that, I suggest you get some input from thepumpguysc. Looking at the last pic you posted, that almost looks like a Bosch pump like they used on Deutz 912 engines, but being Isuzu, I doubt that, but likely a Jap copy of the Bosch. The pump guy might have some useful input for the proper solenoid for that pump.

 

[John V]

@willie59 I think it was 3 wire originally. A bunch of the wires in the harness were melted, so I've had to do some backwards engineering here. In particular one of the stop solenoid wires was completely melted. I know it was a solenoid wire because it had one of those single barrel type connectors like what came with this new solenoid. The electrical schematic shows a 3 wire solenoid. I swapped the original 4JA1 that came with the machine with a 4JB1 since the engine was missing half the parts from a mechanic that gave up half way through, and used 4JB1's were cheap and easy to obtain on alibaba. You're right about the pump though, it's a Zexel which back in the day was licensed by Bosch, now owned by Bosch. It's an inline pump, whereas most 4JB1's used a rotary pump in pickups and vehicles, and that has a different stop solenoid setup, making it difficult to be certain which solenoid is right.

I did find this picture in the service manual for the 55J, which shows the same style stop solenoid as I bought.

 

[John V]

Without displaying the information you received with the solenoid I cannot tell what you bought.
Old machines had solenoids which had a pull in coil and a hold coil.
Your machine was fitted with a more modern style which are electronic and if you start powering the wires around the wrong way you will probably stuff it.
It had a ground wire and a battery wire which stays permanently powered B terminal.
It had an ignition wire (Connected to BR).
The solenoid does nothing when you energize the B wire and does nothing when you energize the BR wire but when you remove power from the BR wire the solenoid will pull in stopping the engine and after a short period relax again.
Its up to you to identify your new solenoids wires.
Regards

The bit that has me confused about this solenoid is which direction is using current, push or pull? The lever on the injection pump kind of defaults to "fuel on". If I don't connect the solenoid to the lever, and try to start the engine, the lever will rotate up to allow fuel. I have to hold it down to stop fuel. So should this solenoid only be drawing current when it needs to pull in, or would it also draw current when extended?

 

[John V]

Is anyone familiar with the little symbols in the schematic? The triangle and square. Are the significant?

 

[Birken Vogt]

Is anyone familiar with the little symbols in the schematic? The triangle and square. Are the significant?

That would tend to indicate a pin and a socket, maybe in or maybe outside of a connector.

The original schematic makes no sense to me because it seems to indicate that middle wire on the solenoid, L/wire 2L, going to terminal B on the key switch, which is battery hot at all times. The upper terminal, LR/wire 2LR, goes to terminal BR which is the run wire, so that makes some sense.

 

[007]

The schematic shows a electronic type stop solenoid.
There is no current flowing in the BR wire.
That only senses the run state of the ignition switch.
When voltage is removed from that wire (as in stop the engine) the circuit card in the back of the solenoid draws power from the B wire to energize the solenoid to stop the engine.

 

[Birken Vogt]

Yes, I see that you explained that earlier now. I think I have only seen that type of solenoid once or twice and never had to work on it or care so it was not fresh in my mind.

 

[007]

Does any one know why Posts in a thread just disappear ?

 

[John V]

Seller sent me a video and confirmed the wiring setup. I had it correct. So they're sending a new one out.

Now on to the glow plugs. Does anyone have a pinout or manual for these 6 pin glow plug timers? P/n 8970405021


I bought a new one since the one on the machine was never switching the glow plug relay. It seems these have two ways of turning on the glow plugs: 1x key on and it will use a timer to turn on the glow plug, and 2. when cranking it always turns on the glow plugs. The new one will turn on the glow plugs for about 0.75 sec. I have confirmed my variable resistance temperature sensor is responding to temperature changes. I'd like to check what values it's expecting from the temp sensor, as well as a spec sheet for how long the timer should stay on for.

Before you ask, yes I called NGK and yes I called Isuzu. Neither could provide me with information about the timer.

 

[John V]

Glow plugs are toast. Will report back after I get new ones.