2007 R25 Yanmar Fuel Alarm Help

[RFSinAK]

Hi All -

I recently picked up a 2007 Ranger R25 with the 110 Yanmar 4JH4-HTE and Type C controls.

First couple of cruises all worked great. On my way back to dock this last trip out the engine panel lit up and an alarm tone sounded. The light that lit up looks like a fuel pump. I have searched the forum and through the engine manual... to no avail. Here is what I need help with:

The manual suggests that the Alarm is to indicate water in the Engine mounted fuel water separator. Sounds good, except I have two fuel filters. The first in line just off the fuel tank is the 10 micron Racor R12T filter/separator. ( I drained the cup, no water - Diesel looks clean. ) Then the fuel flows through the flowscan unit to the engine mounted fuel filter. The manual says there is a filter housing on the engine mounted filter, and a sensor below that. My problem is that my Yanmar does NOT have that style of filter - it’s a black Yanmar 129470-55702 Spin-on fuel filter cartridge. The filter cartridge attaches under a manual primer pump/button with a bleed screw on the side. I see no electrical connections to the engine mounted filter, nor to the racor water separator, which is making me wonder where the water sensor could be ?

Can this alarm be reset ? If so, how?

Is this indicator actually alarming for another condition on my year/model engine? Perhaps low flow? I sort of doubt the latter as I had no trouble cruising at 2600 to 2800 RPM and WOT I was able to reach 3200+ RPM. At the time the alarm occurred I was in my last 1/3 of my tank, but had only run for perhaps 25 nautical miles and all other indicators were looking good. I did not note any unusual engine noise.

I plan to get to my local Yanmar dealer when they re-open on Monday, and I will buy replacement filters for both the Racor and the engine fuel filter, but was hoping for some help from someone who has seen and solved this before.

All help appreciated !

Rob

 

[scross]

Rob,
Replacing both fuel filters is a good start. You can get water contaminated fuel any time you refuel.
We have the Yanmar 4BY2-150 which has a WOT max RPM of 4,000. Is your Yanmar 4JH4 WOT only 3,775 RPM? If you should be getting 3,775 RPM, or close to it, getting only 3,200 RPM could be another issue to explore.

 

[RFSinAK]

Rob,
Replacing both fuel filters is a good start. You can get water contaminated fuel any time you refuel.
We have the Yanmar 4BY2-150 which has a WOT max RPM of 4,000. Is your Yanmar 4JH4 WOT only 3,775 RPM? If you should be getting 3,775 RPM, or close to it, getting only 3,200 RPM could be another issue to explore.

Thanks for the reply...
Near as I can tell the rated WOT for 4JH4 is 3200 /min, and on my outbound I am sure I had that RPM for a few minutes once or twice before dropping back to cruise, on my return I am sure I was briefly at 3000 /min. But 2400 was much more comfortable given conditions.

 

[Favunclerich]

I have a 2008 R-25, and have compared your description to both my boat and the information in the Yanmar parts book. Please send your email address by private message if you would like me to send you a copy.

Based on your description, it seems that your fuel system has been modified from its original design configuration by a previous owner or technician. You should have a 129574-55711 fuel filter with a water sensor 129574-55730 screwed into the bottom of it and sealed with a 129574-55780 o-ring. There should also be a heat shield around the filter 129574-55830. The wire lead from the sensor is supposed to be connected to a white connector about six inches aft of the filter that is part of the wiring harness. My boat also uses a Racor R12P 30 micron primary filter, although that may have changed between 2007 and 2008.

This does not explain why you have an alarm now when there was none recently. My review of the service manual for a Type C instrument panel only shows one alarm related to the fuel system, and that is for water in the fuel. I don't know if the sensor is normally open or closed. It's possible that the previous owner modified the wiring in some way when he did away with the original water-in-fuel sensor. If you want to send me pictures, I'll compare them to my boat, and maybe we can figure something out together.

 

[RFSinAK]

I have a 2008 R-25, and have compared your description to both my boat and the information in the Yanmar parts book. Please send your email address by private message if you would like me to send you a copy.

This does not explain why you have an alarm now when there was none recently. My review of the service manual for a Type C instrument panel only shows one alarm related to the fuel system, and that is for water in the fuel. I don't know if the sensor is normally open or closed. It's possible that the previous owner modified the wiring in some way when he did away with the original water-in-fuel sensor. If you want to send me pictures, I'll compare them to my boat, and maybe we can figure something out together.

Thanks for the assist. PMs sent.

Today’s update - after a bit of time hanging upside down in the bilge tracing the main wiring harness looking for a sensor, I found that the previous owner had done two things - had zip tied the main harness to the engine with minimal protection AND had then supported the 1.25” discharge line for the backup bilge pump from the main harness between that and the three harness connections at the engine. The engine connectors were under a bit of tension. I pulled the harness away from the engine (the black tape was worn through but no signs of the conductors being damaged, found an alternate support for the bilge discharge line, and disconnected, massaged, and reconnected the main plugs. Fired it up, no alarm tone. Sigh. Boat is on the hard, so cant run it for long, but a test cruise is in order.

I will change the fuel filter for good measure regardless, and install proper cable protection on main harness around the engine block, and perhaps put some dielectric on the connections at those main plugs.... and see if the problem comes back once up to temperature or after short cruise.

Can’t figure out how to post photos. Will check the help page and try again.

 

[Bruce Moore]

Can’t figure out how to post photos. Will check the help page and try again.

There are two ways to embed images in your posts. One involves having a photo album on this site. Getting a User Photo Album is easy but it requires submitting a request from within the site structure.

1. Sign on to the site. You’re probably already signed in if you’re reading this.

2. Select the User Control Panel link from the upper left corner of any page. Note: On the home page, this link is in your user menu in the upper right.

3. Click the Usergroups tab, then select the radio button next to the User Albums group.
Scroll down, choose "Join selected" in the drop-down menu, and click the Submit button.

Once you do this, an email is automatically sent to the administrator (me). That message will trigger my ability to approve your request, and you'll receive an email indicating your membership in the User Albums group has been activated.


If the picture you want to include is in one of your gallery folders (on Tugnuts), click on the g2Imgbutton. That will open another window which will allow you to browse your galleries and select a picture. Be patient, it can take a while for the new window to populate. It should default to your album when it opens.


Click the box in the upper left of the picture you want to post. Scroll (way) down to the bottom of the window and click Submit. That will attach the picture to your post.


If the picture isn't in your gallery, perhaps something you've seen elsewhere on the web, or in another personal web collection (i.e. flickr, iCloud, google, etc.) then you click the Img button. The image/collection must be open to the public.


This will create the following string in your posting window - then you copy and paste the URL (http://whatever...jpg) of the desired image in the middle, between the ][ brackets. The trick here is to determine the direct URL of the image. Various image hosting sites show it in different ways. Sometimes it's right up in the address bar. Other times it's listed under "Share This Image", etc.


You can determine if you have the correct URL by hitting the Preview button. If it displays, you're good to go. If it's not correct, the form will give you some kind of clue so you can go back and dig around. You'll only have to figure it out once for each host.


Cheers,


Bruce

 

[knotflying]

Keep in mind that there are times when a "water in fuel" alarm is erroneous. I and others have had it. Sometimes it is related to fuel purchased with additives.

 

[RFSinAK]

Unfortunately ... Still looking for my problem.

Fired up the Yanmar, and the fuel alarm is back. Looks like an intermittent problem, will continue to chase wiring for now as I have checked for water twice and still cant locate any alarm sensor or switch for the issue.

All thoughts welcome !

 

[RFSinAK]

Keep in mind that there are times when a "water in fuel" alarm is erroneous. I and others have had it. Sometimes it is related to fuel purchased with additives.

Thanks Knotflying - I read through a couple dozen posts for these alarms on various engine styles, and pretty much all are equipped with either the Volvo style sensor or the original filter-mounted yanmar water sense switch just below the fuel filter. I could not find anyone having posted an alarm who had a yanmar and did NOT have the fuel filter mounted sense switch.

With Andrews help and referral I reached a rep who told me that Yanmar did not use the same wires for any other purpose on the Yanmar 110HP JH4-HTE, so I am going to go with that, and test out the harness again. If I find that there is any conductivity to ground for that signal from the Type C panel, I will pop the cable connectors apart and test each segment and see if I can find a short or partial short to explain an alarm for which no sensor nor switch is installed. If my suspicion is correct I will find any such short in the last few inches, at the engine itself. The final confirmation will be to disconnect just that one wire before at one of the plugs between the panel and the short circuit, and try it out.

<fingers crossed>

UPDATE: I disconnected the flat connector at the alarm display at the controls. I measured from the wire for the fuel sensor to ground 95KOHMs resistance. I then disconnected the final plug for the same wire at the engine block (the other side of the main wire harness). I measured open circuit - no connection. SO, I took the DVM to the final plug at the engine block and measured 94KOHM to engine ground on that final leg of the circuit. Since they dont use those wires for any other connection to the fuel system, just the ‘standard’ water sense switch at the filter, I cut the wire at the engine plug where I had some access and length to repair it if needed. Reassembled the connections and measured again at the Final control panel connection - open circuit. No sensor, no short circuit, so I flipped the main switches on and fired it up.

No Alarm.

If I replace the spin on filter with the newer version with water sensor I will have to replace that last 24” cable from the wiring harness engine block plug to the new sense switch, but for now I can operate without the phantom alarm. Hoping I have no regrets for the work... but if I replace the fuel filter with the sensor version and connect it all and it works as it should - vindicated. My working theory - the connector dropped down behind the fuel pump, and vibrated until it dropped further through into that tight gap, where the engine vibration wore through the connector or the insulation in that last wire, creating a short circuit and triggering the alarm and display. Its well-stuck in there, so I cant be 100% sure without removing the fuel pump and pulling that wire end loose for inspection, and that is not something I am ready to do at this time. If that fuel pump gets serviced ... I’ll find out then.