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Topic: Emergency. Engine wont shut down (Read 2189 times) previous topic - next topic

Emergency. Engine wont shut down

93 U225 with baby cummins.
Can NOT get engine to shut off.
At a Loves currently and trying to find fuel shut off.

Any help appreciated

Re: Emergency. Engine wont shut down

Reply #1 –
Need to stop either the air or the fuel.

Re: Emergency. Engine wont shut down

Reply #2 –
Possibly the fuel shutoff solenoid is stuck in the retracted position?

5.9 solenoid might look different than our 8.3 but should be in the same general vicinity - passenger side of engine next to fuel injection pump.

Either tap on the solenoid to see if it will release, or pull the cotter pin and disconnect from fuel lever on injection pump.

See photos of 5.9 solenoid in links below:

Fuel Shutoff Solenoid Problem? | Cummins Diesel Forum

Fuel Shutoff Solenoid ? | Cummins Diesel Forum



Re: Emergency. Engine wont shut down

Reply #3 –
Moby..... what did you find?
 

Re: Emergency. Engine wont shut down

Reply #4 –
Found not much, really.
I was at s Loves and found the most grizzled mechanic there.  He sounded like he knew what he was talking about and diagnosed a bad fuel shut off relay.
I managed to get her to shut down by placing my hand over the air intake on front of the turbo.
Two things remain.
1)  I'm not above some percussion therapy, and I could not find the valve in question as I had to hit the road.  WTF does the fuel pump look like?
2)  If I CAN'T locate it,  anybody know a good mechanic in the Joshua Tree area?
 Specifically Desert Hot Springs area.

Re: Emergency. Engine wont shut down

Reply #5 –
Try disconnecting the battery to shut off,no juice fuel valve should shut off.

Re: Emergency. Engine wont shut down

Reply #6 –

I encountered same issue on my 91 GV. When I turned the key off, everything is still running like nothing happened. The cause was the bad main ignition solenoid. It was terrifying, but I messed with this coach for so long I know what is going on. I used a wood stick to tap the top of the solenoid, and everything just shut off like it should be. I guess the contact inside the solenoid is corroded after so many years and stick together. A little tap helped.

I then replaced it with Cole Hersee 24213. Everything is working much better after replacement. Don't buy from Amazon warehouse. Buy new. Don't ask me why.

It also addresses my issue of Transmission Do Not Shift issue and few other ones.

After the new solenoid, the lights on the dashboard are significantly brighter.

If you coach is 93 and you are not aware of any replacement of the main ignition solenoid, I think you should check it out. Super easy to change.

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Emergency. Engine wont shut down

Reply #7 –
How does the start solenoid affect the engine still running?

Re: Emergency. Engine wont shut down

Reply #9 –
I could understand the main ignition solenoid causing this but not the start solenoid. 🤷‍♂️

Re: Emergency. Engine wont shut down

Reply #11 –
Common confusion encountered on this Forum, due to using incorrect terminology.

There are three different solenoids involved in Cummins powered coach starting sequence (perhaps the same with other engines - IDK):

1.  IGNITION solenoid (located up front somewhere, under the dash cover or behind passenger kick panel in later coaches).

2.  AUX START solenoid (located at the back end somewhere, usually near the isolator panel).

3.  STARTER solenoid (mounted on the starter motor)

There may also be a RELAY involved in directing power to the FUEL SHUTOFF solenoid.  This sounds like the item to which Moby's "grizzled mechanic" referred.  If the relay was to stick in the closed position, it would keep the FUEL SHUTOFF solenoid energized, which would prevent engine shutdown.  Sounds like a good possibility to check out!

Re: Emergency. Engine wont shut down

Reply #12 –
Quote from: Chuck & Jeannie –
FUEL SHUTOFF solenoid energized, which would prevent engine shutdown.
That was my first thought as well. If the fuel shutoff solenoid closes, the engine will stop.  Been there done that with a 8.3 cummins mechanical engine in a prevous coach.

Re: Emergency. Engine wont shut down

Reply #13 –
Quote from: John44 –
Try disconnecting the battery to shut off,no juice fuel valve should shut off.

I would NOT do that.  An alternator feeding an open circuit is not a good idea.

Have not worked on that vintage B engine, but wonder if the fuel shutoff valve is the same?

Re: Emergency. Engine wont shut down

Reply #14 –
Quote from: wolfe10 –
Have not worked on that vintage B engine, but wonder if the fuel shutoff valve is the same?
I believe it is very similar to the 8.3 with slightly different lever shape and solenoid mount.  See the links in Reply #2.

Re: Emergency. Engine wont shut down

Reply #15 –
Quote from: Moby –
I managed to get her to shut down by placing my hand over the air intake on front of the turbo.

I'd caution against this!  It's a potential diesel powered meat grinder.


Re: Emergency. Engine wont shut down

Reply #17 –
Have you figured out the issue?

Re: Emergency. Engine wont shut down

Reply #18 –
The 5.9 Cummins fuel shut off is almost identical to the C8.3 with exception of the connection on the fuel shut off - the diameter of the 5.9 is slightly smaller than 8.3. They wire and bolt up the same and if you have the adjusting rod that fits your engine you are generally good to go. The three electrical pins on my C8.3 are round.

You have three wires - red, white, and black. Red is energized by starter position on ignition switch and white is energized by ignition switch in the run position. The pull down coil is energized at start and the hold in is energized by run. Both coils contained in single fuel shut off solenoid.

The solenoid has a rubber cover to keep crud out of the piston or puck that the coil pulls and holds. That cover deteriorates and the puck gets pitted, and gunked up , Which can keep it from fully opening the fuel valve or theoretically hang up in the run position. You could either "help" it closed with your hand, pull the connector to kill power to fuel solenoid, or you could remove the little cotter pin and disconnect solenoid from fuel shut off valve. I've had mine fail to open fuel valve fully because of crud and corrosion ( max speed 10 mph) and the hold in circuit failed (started and immediately stopped when key released.)

Lift up your engine cover, the shut off solenoid is on passenger side of engine, mounted to block, and next to throttle linkage. The coils are facing up and the connecting lever is facing down toward ground. The protective cover may be mostly gone.

Re: Emergency. Engine wont shut down

Reply #19 –
Update:
 The solenoid suffered from unplanned disassembly.
New part installed, just have to wire up the Connectors.

 News coming soon.