YDS Error 29 "Intake Pressure Sensor"

[marmstufl]

All,

After switching out a faulty ECU, it looks like my "piston wash" issue was a thing of the past, boat has been running great for months now. Prior issue in this thread (led to 3 blown engines.. covered by warranties thank god): https://jetboaters.net/threads/knocking-sound-on-starboard-engine-ar230.13807/#post-245462


I've really taken to trying to learn how every little nuance of the boat works (mainly to calm down my OCD/PTSD from the blown engines ), so I got the Yamaha YDS software to get extra preemptive with my maintenance.

Out on the bay last week I got a temperature warning, I've gotten this warning once before.. but just figured I had an obstruction or some debris. Both times I've gotten this warning it went away after I switched the engine off and turned it back on, so it lends a little credence to minor obstructions. When I hooked up the YDS software I got the "Error 29 - Intake Press Sensor". I ordered a new Intake Pressure Sensor from ebay for like 55 bucks, but have yet to see exactly what purpose this thing does. From some google searches it seems like it helps control fuel injection at low RPMs, is this true? The motor seems to be running just fine, oil levels are good, however it did get a tad bit finnicky at lower RPMS, so I'm thinking this may be the issue. By finnicky I mean when I first got the engine back it would sometimes immediately die after I fired it up, or the RPMs would fluctuate wildly (then they'd settle down after a few minutes of operation). These issues seemed to have remedied themselves after I toyed with the ICV. The new engine was at 300-400 less RPM's than the port side, but the ICV tweaks fixed it.

IMG_20180505_105210

• marmstufl
• May 6, 2018

YDS Error 29

Long story short, anyone have any experience with this error code and can you tell me exactly what this sensor does? Other than that, the boat is running great.

 

[Julian]

I'm no help on this one, but I also googled it and found a thread on THT where the guy solved his problem with:

Believe that I found the problem. I took a shot and sprayed each injector with silicone looking for a leak. When I hit number 4 it revved up..Took off the intake and found the #4 injector gasket in the bottom of the motor. No gasket on #4 cylinder. Put it back on and seems to run fine. I hope thats it??​

This is the thread....hopefully others will assist you...but this thread does some explaining of what the code is for also.

 

[marmstufl]

Thanks Julian. I saw that too, but I don't think I have any compression issues (at least I think). I can play with the ICV to get the RPMs just right, and after a month or so the idle problems started to go away. I'm wondering if it was just the new ECM getting into sync? Or maybe that's just a placebo for me .

 

[Scottintexas]

I don't know about the sensor but we have another member with a 2008 that had flashing left in the cooling line that restricted flow and would cause an intermittent overheat,
it's shown in this video,
https://jetboaters.net/faq/how-does-the-water-actually-flow-through-my-yamaha-engine.75/

 

[buckbuck]

I am that guy. Since you have a 2008 make sure you pull your Y fitting and look thru it. Yamaha had a batch that were partially blocked in 2008. Another thing to consider is the Throttle Position Sensor. I never had a performance issue with the throttle open. Just when at idle I would have fluctuating rpm. I found it by connecting the YDS and observing the spark advance.

 

[marmstufl]

I am that guy. Since you have a 2008 make sure you pull your Y fitting and look thru it. Yamaha had a batch that were partially blocked in 2008. Another thing to consider is the Throttle Position Sensor. I never had a performance issue with the throttle open. Just when at idle I would have fluctuating rpm. I found it by connecting the YDS and observing the spark advance.

You know what.. now that I think about it, this may be something to look at. I got a temp warning when I had the engine (Starboard) on the hose and never received that before. I'll get a compressor and blow those suckers out.

 

[Scottintexas]

The y-fitting that buck had the flashing in is not something you can "blow out", it's left over material that you have to cut out, if you watch his video he shows you a picture of it,

if you're getting an alarm I don't think it will be anything you can just blow out with air,

 

[buckbuck]

As @Scottintexas said, it is unlikely you will blow those out. I had to take a 7/16" drill bit as a punch and knock them out. The picture below is the Y fitting. It is not hard to get to and relatedly easy to remove. I suggest you take the time to examine them.

 

[marmstufl]

Thank you a ton for this, I'll check it out and get back to let ya'll know what I find.