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BF 225 Pgm-Fi engine over temp....

huntermanryan

New member
Hi all, new to this forum and I'm kind of at my wits end on this one, looking for some assistance.
I have a 2013 BF225. After idling for a few minutes at the ramp, and passed no wake zone, I can jump up on a plane and after about 15-20 seconds it will SOMETIMES show an alarm on the Garmin indicator PGM-FI Engine Over Temperature. This puts The motor briefly into limp mode until I bring boat down to an Idle. As soon as I idle down, limp mode clears up, alarm goes away, and the issue likely won't arise again on that trip. The motor is not overheating, not even close. The temp gauge shows between 170-200 depending on RPM. Here's what I have done so far:
-Replaced both t-stats
-Replaced Temp sensors on exhaust manifold
-Replaced impeller
-Inspected manifolds with borescope for corrosion or blockages with borescope (very clean, no significant corrosion)
-With motor running at idle, shot the manifolds with IR temp meter, nothing abnormal.
-Ran a descaler treatment through the motor just in case, no changes.

Most of these parts are maintenance items anyhow, so I didn't mind replacing them for the sale of good measure, but this intermittent alarm keeps going, and is not repeatable on command if you will. Is it possible to that there is something other than the temperature system giving me this error, like possibly a coil occasionally going out under load? Or maybe an O2 sensor? I really don't want to keep throwing money at the wrong problem. Any help or suggestions are appreciated.
I'm have attached an image I took of the error message that comes up, but again, it cleared itself as soon as I come to idle.
 
Image didn't show up.

OK, let's start with the basics. Pull Codes. The procedure for doing that is attached. And what the codes mean is also attached. There is a 3rd temp sensor on the block between the V. It's a PITA to get to and requires the removal of at least one head. That is the block temp sensor and it's the one that your Garmin is likely monitoring. However, it doesn't alarm until the block temp exceeds ~225 F or more.

When you pull codes and get six blinks, then repeats, that's block sensor, Honda labels it the ECT for Engine Coolant Temperature. Before pulling the head, however, fish around in there for a 6-prong connector coming out of that V area. Unplug it and thoroughly inspect and clean it. That COULD solve the problem.

A coil going out under load will give you a code 1. So will a plug misfire, or a failed HO2 sensor.
 

Attachments

  • Procedure for Getting Fault Codes.pdf
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  • MIL Fault Codes Scanned.pdf
    85.1 KB · Views: 37
Image didn't show up.

OK, let's start with the basics. Pull Codes. The procedure for doing that is attached. And what the codes mean is also attached. There is a 3rd temp sensor on the block between the V. It's a PITA to get to and requires the removal of at least one head. That is the block temp sensor and it's the one that your Garmin is likely monitoring. However, it doesn't alarm until the block temp exceeds ~225 F or more.

When you pull codes and get six blinks, then repeats, that's block sensor, Honda labels it the ECT for Engine Coolant Temperature. Before pulling the head, however, fish around in there for a 6-prong connector coming out of that V area. Unplug it and thoroughly inspect and clean it. That COULD solve the problem.

A coil going out under load will give you a code 1. So will a plug misfire, or a failed HO2 sensor.
Man that helped out so much! Ive had Honda motors for years, but never knew this method to check for codes. Turns out I'm getting the 1 blink every 3 seconds. This is the code for H02 Sensor. Ive had 02 sensors fail on other Honda's but never have had them put me into limp mode until I bring to Idle, so I'm leaning more towards it being a misfire when under load, like a coil going bad or a plug. It still doesnt make sense to me why my Garmin might display an overtemp warning (while at the same time the garmin is displaying normal temp ranges). I wonder if the overtemp display is just something that comes up default when hitting limp mode. I definitley have had a Honda Mini-Van (same motor) go into limp mode over a bad coil, and you could cycle power and run it just fine until it hit that miss again and went limp mode.

Any tricks to checking for which coil or plug might be the issue when its not actually a full time miss? Or any idea how to rule out completely an H02 Sensor?
 
I just unplugged each coil with motor at idle. Each coil I unplugged gave me a new dead miss, so that verifies that it's not missing (at least at idle anyhow)
 
Correct, a failed HO2 sensor will not by itself put you in LIMP mode. The BF 225 goes into LIMP mode under 2 conditions - 1. low oil pressure where the engine will keep running in LIMP mode, and secondly, an overheat, where it will go into LIMP mode for about 20 seconds, and if not resolved, it will shut down.

Use an IR heat gun to confirm you are not really overheating - shoot the manifolds AND the block at several places.

Agree with NSDON - pull the plugs and inspect anodes. They should be milk chocolate brown. If blackened, you are getting too much fuel in the cylinders. If bright, not enough fuel OR you may be getting water in the cylinders. Inspect all of the plugs. Only one may be causing a problem.

BTW - fuel pressure out of spec can also cause a 1 blink. Check fuel pressure. There is a bolt on the top of the HP fuel filter for relieving fuel pressure. Remove it and attach the fuel pressure gauge there. You may need a 6 mm adapter. Remove vacuum hose from the fuel regulator and plug it or pinch it closed. Run the engine until it's warmed up. Fuel pressure should be between 41 psi and 48 psi, it my memory is still good.

If fuel pressure is out of spec, come back to us and I, and hopefully others, will try to walk you through some diagnostics.

Going into LIMP mode is still bothering me. LIMP mode is 1800 RPM. Is that what you experienced?
 
Update! Pretty sure I got it this time. I pulled and inspected all plugs, they look great (replaced them last year, so as expected). I put an IR gun on the block and manifolds already, nothing was abnormal. I went ahead and pulled the 02 sensor, it had a bit of soot built up on it, but nothing crazy. Cleaned to H02 up a bit and re-installed. I cleared all codes and took the boat out. Now I'm getting an audible alarm, billinking code "01" and the motor itself runs great, doesn't go into limp for any reason. In my previous experiences with these motors, it's acting exactly like an H02 now. Going to order one, but dang these things are not cheap.
Anyone know of a less expensive alternative to the OEM # 35655-ZY3-C01 ??? Over $300 for an 02 is nuts.
 
Good to hear. Here is a post I copied and saved a while back...

Boats.net now has a Honda sensor that is cheaper than the Walker. I believe it's the same sensor, just a different stock number. I have been using the new stock number one for about 12 months now.

35655-zy3-c01 original number (about $355)

06356-zy3-307 new number (about ($60)

Also, Walker HO2 sensors seem to have proven themselves. Walker 932-24008 (14mm base)
 
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