How does HMMWV shut down? Fuel shut off solenoid questions.

[Mainsail]

I actually looked at that one when I followed your link earlier and that one is cheap chinese crap. I did find some New OEM and some New "Made in Italy" replacement 24v 26387 solenoids on ebay between $37-95.

From what I remember the German ones are the best.

 

[springer1981]

From what I remember the German ones are the best.

Personally I think any quality manufacturing process is going to be equal. In my personal experience the cheap crap coming out of china is not a quality manufacturing process using quality components. A solenoids construction is pretty simple, copper wire coil, insulator, steel plunger and epoxy casing for example. The way to skimp on the components is using cheaper wire, thinner wire gauge, cast steel, low temp epoxy, etc. The quality of the machining on the plunger would be an example of manufacturing process. Cheap chinese parts often have much rougher surfaces due to speed of machining. German or other quality parts will have a much finer machining and take longer and cost more. Because of that they also usually work better and wear less.

I'm not saying ALL chinese parts are crap or poor quality but there are just too many counterfeit parts and low cost crap to risk it IMO. I'd pay extra for a German or Italian or OEM part before saving $20 on a chinese part that I want to depend on.

 

[TOBASH]

The more I read this thread the more I agree with papakb. This is a potentially dangerous project that is a fool’s errand. You will create a runaway unstoppable engine and you will be farked. The only way to do this is to manually activate the existing cutoff, but why?

I believe papakb has offered sage advice. Anything more is

Good luck on your quest. I’m out.

 

[nikojo]

Why go to all this work, to remove one wire?

For me it’s not just about removing one wire. It’s removing a component that “can” fail and strand you. Ideally if there was a way to make it work it would be better.

I didn’t understand this part of the system but thanks to all of you I now understand this much better.

It’s clear that bypassing this part of system would deprive the IP of linricsting fuel, albeit briefly, which isn’t a good idea. So “net-net” would keep it OEM unless otherwise.

 

[87cr250r]

You can install the ETSO solenoid in your pump housing and eliminate this risk of failure. The ETSO solenoid can only fail in a run position. It also allows the engine to keep running if you lose an alternator. It allows the engine to run without any draw on the batteries. This part is available from the OEM. It can be easily installed with the pump on engine.

 

[nikojo]

engine is allowed all the air it wants at anytime but the fuel is changed to control the engines RPM's. If you stop the air the engine also stops. It would seem the best method to emergency stop the engine would be to introduce an air block off of some type. A large butterfly valve similar to a wood stove dampener that is cable operated would be pretty easy to do. However, the relative ease of killing the power to the solenoid with a switch would be just as effective IMO.

There are these devices made for semi-trucks in case of “runaway” from engine oil feeding the engine combustion in which the only way to stop is with “stall” the engine or cut off air. It is manually deployed by pulling a cable. The butterfly is spring actuated.

I’ve thought of adding this too lol.

 

[springer1981]

You can install the ETSO solenoid in your pump housing and eliminate this risk of failure. The ETSO solenoid can only fail in a run position. It also allows the engine to keep running if you lose an alternator. It allows the engine to run without any draw on the batteries. This part is available from the OEM. It can be easily installed with the pump on engine.

You would have to change the shut off circuit to be momentary or add a shut off button to apply power to shut it off. Does the alternator directly drive the ESO or would it stay running on strictly battery power?

 

[nikojo]

The more I read this thread the more I agree with papakb. This is a potentially dangerous project that is a fool’s errand. You will create a runaway unstoppable engine and you will be farked. The only way to do this is to manually activate the existing cutoff, but why?

I believe papakb has offered sage advice. Anything more is

Good luck on your quest. I’m out.

I don't disagree. I'm still glad I asked the question as I've learned a lot and understand this part much better.

Don't see how it would dangerous. Only way it would turn into a runaway is WITH the solenoid and IF the solenoid is installed with the lever malpositioned. This is how it exists right now on our rigs. The pdf that "8" posted explains this best and is very instructive if you ever have to change out your OEM solenoid. It references a 'retaining tool' which I can't find but looks easy to make.

Regarding "energize to run" (our system) versus " energize to stop".........does the solenoid care, ie does it wear or fail more quickly when it's energized constantly versus occasionally??

 

[nikojo]

You can install the ETSO solenoid in your pump housing and eliminate this risk of failure. The ETSO solenoid can only fail in a run position. It also allows the engine to keep running if you lose an alternator. It allows the engine to run without any draw on the batteries. This part is available from the OEM. It can be easily installed with the pump on engine.

Well then this was worth it LOL! Thank you "8". Unless someone can give a reason why not to use ETSO I will likely switch to it.

BTW the only reason I am bringing this up is I was planning on changing the OEM solenoid as the truck is 20 years old and just thought it prudent. This is partly why I started the thread.

As others have said, quality of solenoid is important. The amazon ones have a few descriptions of failures, one showing the epoxy disintegrating and trashing the IP.

Does anyone have a link to a good quality solenoid for ETSO??

 

[nikojo]

You can install the ETSO solenoid in your pump housing and eliminate this risk of failure. The ETSO solenoid can only fail in a run position. It also allows the engine to keep running if you lose an alternator. It allows the engine to run without any draw on the batteries. This part is available from the OEM. It can be easily installed with the pump on engine.

"8" are you certain our pumps have that triangular piece that the ETSO solenoid needs??

I've attached diagram from your PDF.

 

[springer1981]

"8" are you certain our pumps have that triangular piece that the ETSO solenoid needs??

View attachment 888071I've attached diagram from your PDF.

Here's the part number Stanadyne 26922 but after a quick search, it seems to be a rare part since it isn't the standard way of doing it. Interestingly enough, you can find pictures of the part and it is the same solenoid mounted in reverse with a different lever on it. You could probably modify the existing solenoid and mount is backwards. Make sure you post pictures for us of whatever you do.

 

[nikojo]

It does appear our systems have the triangular piece that would allow using ETSO solenoid. Pics below.

Here are some pics from a thread discussing this mechanism. Credit of the pics to this thread linked here.

G503 Military Vehicle Message Forums - Login

Pic 1: solenoid with the lever in 'non running' position. Solenoid would be 'off' here. The lever is pushing the fuel cutoff lever into 'off' position by pushing the arm towards the rear of the housing (right side of picture).

Pic 2: shows the solenoid with the lever in 'running' position. Solenoid is 'on' and energized and is pulling the lever arm back into the housing. This allows the fuel cutoff arm to go towards front of housing (left side of picture). This allows fuel into the IP.

Pic 3: The fuel cutoff mechanism is visible here (upper part pic in housing at floor). This has a spring which by default keeps it 'pushed' toward the front of the housing (left side of pic). Towards the rear of the housing (right side of pic at floor) you can see a pivot mechanism that directly cuts off the fuel as "8" described. When the solenoid is "on" and energized it pulls the lever arm of the solenoid towards the solenoid which allows the arm of the fuel cutoff mechanism to go towards the front of the housing and engaging the pivot arm to 'open' the fuel to the IP.

Pic 4: When the solenoid is "off" there is a spring on the solenoid that keeps the lever arm out from the solenoid and pushes the arm of the fuel cutoff mechanism towards the rear of the housing (towards right side of pic). This engages the pivot arm into a fuel "off" position for the IP. The finger in the picture is essentially acting like the de-energized solenoid lever arm and pushing the mechanism towards the rear of the housing (towards right side of pic).



In the third pic towards the upper left of housing you can see the triangular part coming off the mechanism that the ETSO solenoid would engage. This would essentially be in the reverse of what was just desribed.

 

[87cr250r]

I have personally had to swap the solenoid on a DB4 pump that was mis-ordered.

I purchased the ETSO solenoid for a 24V application through Diamond Diesel but any Stanadyne distributor should be able to order one.

 

[nikojo]

I have personally had to swap the solenoid on a DB4 pump that was mis-ordered.

I purchased the ETSO solenoid for a 24V application through Diamond Diesel but any Stanadyne distributor should be able to order one.

I understand you would have to 'rewire' to use a momentary switch or button. Do you know where that wire goes? Back to the run switch?? Or the starter box??

 

[nikojo]

Here is a great youtube video demonstrating how the fuel is delivered and explains the fuel shut off a bit.

Interestingly it mentions that if the 'return' is blocked or plugged that the engine will stall as the pressure equalizes on both sides of the pistons.

It's also interesting to note that the cold advance solenoid essentially when active 'blocks' the return partially to make the timing advance.

Could this be a way to then stop the engine, ie have a manual switch that blocks that part of the return? That won't allow the pump to go dry.

Have to think it's not a good idea as the pressure in the housing would get to a high level and cause gasket failure or some other problem.

 

[Milcommoguy]

Thinking of another hobby for 2023. Something simple like basket weaving, CAMO

 

[nikojo]

Thinking of another hobby for 2023. Something simple like basket weaving, CAMO

Ha! I'm trying to stimulate you to invent a kit similar to the camobox (which is excellent) that I can use to get rid of my solenoid.

I clearly hate solenoids......even more than hemorrhoids.

 

[Mogman]

I understand you would have to 'rewire' to use a momentary switch or button. Do you know where that wire goes? Back to the run switch?? Or the starter box??

You would run a battery hot all the time wire through a momentary switch to the solenoid, the only time it would be used it to shut down the engine, any time the engine starts turning it will try to run, you must have 24V available to shut it down so that opens a whole new can of worms in your dooms day anything can fail and must be able to be bypassed scenario.

 

[Milcommoguy]

I appreciate the academics, mechanics, brain teaser, bah bah bah of this thread... I DO. Solenoids are very reliable ( no statistics ) and simple to understand.

If something is going to break on a HMMWV least likely would be the IP solenoid IMO. And if it does, after 58 and counting posts, I am now an expert on that now. LOL

To build a better mouse trap or IP. You hate soleniods... I'am not to fond of Smart Boxes, CAMO

EVERYONE have a great HUM- dinginger year.

 

[nikojo]

You would run a battery hot all the time wire through a momentary switch to the solenoid, the only time it would be used it to shut down the engine, any time the engine starts turning it will try to run, you must have 24V available to shut it down so that opens a whole new can of worms in your dooms day anything can fail and must be able to be bypassed scenario.

Do you know where the wire originates that goes to the normal solenoid? Does it come from the 'run' switch?

That way I can use that and tap into 24V locally and create the momentary switch. Doesn't seem it would be complicated to do that everything else aside.