Cat 3116 Fuel Solenoid

EKM

EKM

Active Member
Feb 4, 2007
674
Beach Haven, NJ
Boat Info
2000 420AC
Engines
Cummins 6CTA
Took my boat out for my the first trip and when I stopped and tried to restart the Port, it would turn over but not fire up. It was missing the clunk sound of the SV. Jumped into the engine room and disconnected on wire and re-attached and the clunk came back (and engine fired up too). Left the rocker switch on while doing this test.

Any suggestions on what the issue is?
 
Sticking fuel supply solenoid…………the one on the front of the fuel pump. It is easy to change but requires a pin type spanner wrench.
 
Last edited:
Frank, is that what happened to Robert's friend (with the same boat and engines as Ed has) in Atlantic City?
 
Can this be cleaned or just replace it? Is this an OEM part only or where to find?
Thanks,
Ed
 
First, what wire did you remove and jump?

If it is the fuel supply solenoid on the pump, then it is an OEM part and will have to come from either a Caterpillar dealer or perhaps a diesel specialty company that prepares and rebuilds injectors and pumps. Most injection systems are not OEM anyway but are supplied by Bosch, Stanadyne, Roosa, etc.
 
I loosen one of the eyelets and pulled only one off and when I powered or grounded it the SV started actuating again. I left the ignition circuit on during this so knew right away that it was pulling in the SV (nice clunk). I assume this is the fuel supply SV on the pump. It sits on the starboard side of the engine in front of the coolant tank and in alignment with the cylinder head.

Thanks for the guidance Frank!
 
Ed,

Bear with me because this is the only photo I can find:

http://marine-engine-blog.blogspot.com/2015_05_01_archive.html


Go to this site then scroll down until you get to several color photos of a 3116….the heading is something about alternators, but look that the photo and see if you see the gold colored round thing with the blue boot on the back end. That is the fuel supply solenoid.

There is another relay on the transmission end of the engine that looks like an old Ford truck starter solenoid.

https://www.tomsbroncoparts.com/product/starter-solenoid-66-79-ford-bronco-new


It kind of acts like a slave solenoid on a Mercruiser engine. That must trigger and close for there to be power applied to the fuel solenoid in the picture.

If you are jumping the "Ford truck solenoid", then the fix is a lot cheaper, but you will need the relay Cat specifies……I think it is going to be a constant duty rather than one for intermittent duty.
 
Its the fuel relay wiring that I disconnected to get my clunk back. Not sure if you can remove and lube as it sounds like there is a linkage in there. I assume you are not opening up the fuel system by removing this relay. Still could be electrical but need the problem to come back to troubleshoot.
Frank....thanks for the write up!
 
I've never tried to repair one that was intermittent. If the problem is a sticking plunger, you might polish it and get going, but there is a coil and spring that has to function properly as well. You aren't going to affect how much pull you get from the coil by trying to clean the plunger. Since this is the only electrical component in the fuel circuit on a 3116, it has the potential to leave you stranded if it totally fails. I'd probably replace it rather than trying to repairing it.
 
fwebster said:
I've never tried to repair one that was intermittent. If the problem is a sticking plunger, you might polish it and get going, but there is a coil and spring that has to function properly as well. You aren't going to affect how much pull you get from the coil by trying to clean the plunger. Since this is the only electrical component in the fuel circuit on a 3116, it has the potential to leave you stranded if it totally fails. I'd probably replace it rather than trying to repairing it.
Click to expand...
Frank, I your opinion, is this enough of a concern to carry a spare? Thanks for your continuing wisdom!
 
fwebster said:
Ed,

Bear with me because this is the only photo I can find:

http://marine-engine-blog.blogspot.com/2015_05_01_archive.html


Go to this site then scroll down until you get to several color photos of a 3116….the heading is something about alternators, but look that the photo and see if you see the gold colored round thing with the blue boot on the back end. That is the fuel supply solenoid.

There is another relay on the transmission end of the engine that looks like an old Ford truck starter solenoid.

https://www.tomsbroncoparts.com/product/starter-solenoid-66-79-ford-bronco-new


It kind of acts like a slave solenoid on a Mercruiser engine. That must trigger and close for there to be power applied to the fuel solenoid in the picture.

If you are jumping the "Ford truck solenoid", then the fix is a lot cheaper, but you will need the relay Cat specifies……I think it is going to be a constant duty rather than one for intermittent duty.
Click to expand...

Frank - thanks for the great link to the blogspot. Plenty of "homework" reading (and understanding) all that info. Great stuff!
 
I once had a similar problem where I wouldn't hear the clunk until I switched the switch a few times. I thought it was the fuel solenoid as well. But eventually the motor started dying during operation as well and it turned out be a relay between the switch on the helm and the fuel solenoid. It was located in a rectangular box mounted on the of the transmission. Also found have the screws in the box loose as well. Not sure your year model had that same box, but thought I would mention my situation.

Good luck,

Pete
 
The cat part number is 0302266, around $80.00. Just replaced the item this week. If you do not have the box, it is located on the aft port side near the top. It is a cylinder about the size of two golf balls.

Big shout out to Frank for helping me isolate the issue of my engine not starting.


Sent from my iPhone using Tapatalk
 
I used a voltmeter to validate the part was in fact the issue. I also made a point to disconnect the positive side for both batteries.

To validate the issue (before disconnecting batteries), I found the hot pole on the relay, which was the starboard pole on my engines. I then connected the voltmeter to the opposite pole and attempted to start the engine. When I pressed the start button on the helm, the relay was not powering on that pole.

I labeled all the wires on the relay to ensure I put them back properly.

Below is a picture of what I replaced.
7a31fe4e31f97ee18ada540d3fc31820.jpg



Sent from my iPhone using Tapatalk
 
We are talking about 2 different issues here……….

EKM …..has an engine that will crank but will not fire. His fuel supply solenoid is bad.

Prosideus & Pete……..had a problem where the engine wouldn't crank. The relay triggering their starter solenoid is bad. On earlier engines, the relay looks like the one pictured in the previous post by Prosideus; Pete has a later year and he has the control box with several Bosch type plug in relays in it.


We have several Cat 3116/3126 boat in our marina. Some are right at 20 years old and the only relays to fail yet have been the little black Bosch type one in the later engines. I would definitely carry one or more of them as spares. I have the older type and I do carry one of the relays in my spares, but that relay can easily be jumped if it fails so it would be easy to fire up your engine even if the relay failed.
 
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