2005 SX230 will no start on ramp

[JDoumont]

I reticently picked up an 2005 SX230. Boat runs great with one exception. when on the boat ramp at a slight angle the starboard engine will not start. I can get it to start and hold it up around 3-4 K and it will stay running. In the driveway or once in the water and the boat becomes "level" it will start right up and idle just fine. 99% of the time this engine will also not enter no wake mode. (found a helpful thread on that but no success yet)

 

[Scottintexas]

I wonder if you have debris in your tank? Being a new to you boat there is really no telling what might have happened, I might pull the fuel senders and try to look down into the tank,

update your profile with your location so we know where you're at,
look at the link in my sig. below for some good topics about your boat,


.

 

[Gym]

You may have water or moisture in your connectors. I had a similar issue. in the aft starboard locker there is a white, 6 inch round cover. Remove the cover. inside is a wire bundle with about 6 modular connectors. Take 1 apart at a time and check for water and corroded pins. Continue with 1 connector at a time till you get through all of them. Some are tough to reach. You may need to pull them gently towards the opening to access them.

 

[JDoumont]

Thanks for the suggestions I will check them out.

 

[JDoumont]

Thanks for the suggestions I will check them out.

I dealt with this issue all last season, now testing with YDS, I find that my TPS voltage fluctuates a little. at idle this transfers to only about one degree of throttle but at full throttle this is 10 to 15 degrees. It fluctuates even when no changes are being made. I do see it acknowledging the no wake mode button while monitoring the engine but it never enters no wake mode. I purchased a new TPS sensor I get the same readings. if I adjust the throttle screw up enough that the engine will start cold once it warms up it jumps up to 2500 rpm as an idol. Open for suggestions.... Thanks.

 

[WREKS]

Have you tried swapping the no-wake switches?

 

[JDoumont]

Yes, and both switches are new. When I monitor the engine with the YDS soft where it shows the no-wake switch being pushed. So I don't think it's an issue with the no-wake switch or the wiring from it.

 

[dgfreeze]

Good chance the TPS is reacting to the underlying issue when it’s doing its dance. Sounds a lot like a lean condition, but there are a lot of things that could be the problem. Next thing I’d do is duplicate the no start at home. Raise the front of your boat somehow far enough to where you have the no start condition, which will give you something to actually chase. Have you checked your ECU for moisture? Do you top your fuel tank off after every trip? If you run the level down a ways, does it act the same? Not much changes on an EFI engine from sitting level to being on an incline, I’d be looking really hard at the fuel delivery system, and the ECU, due to the known water ingestion issue.

 

[WREKS]

@buckbuck mentions in thread "No wake mode not working" post #5 a bypass motorized valve not working. Have you checked the connections to it?

 

[kjr6306]

I dealt with this issue all last season, now testing with YDS, I find that my TPS voltage fluctuates a little. at idle this transfers to only about one degree of throttle but at full throttle this is 10 to 15 degrees. It fluctuates even when no changes are being made. I do see it acknowledging the no wake mode button while monitoring the engine but it never enters no wake mode. I purchased a new TPS sensor I get the same readings. if I adjust the throttle screw up enough that the engine will start cold once it warms up it jumps up to 2500 rpm as an idol. Open for suggestions.... Thanks.

Did you ever fix this issue? Having essentially the same problem.

 

[Babin Farms]

Did you ever fix this issue? Having essentially the same problem.

Have you recently had any other issues or worked on the boat? Will it not crank over or crank & no start?

 

[kjr6306]

Yes. I had the engine out and replaced the head due to a cracked head. I am suspecting a TB issue. Odd issue. The engine starts and idles fine on the trailer and with the hose on it. As soon as I put it in the water the engine will not run without increasing the idle set screw on the throttle cable. Once the engine gets running in the water and essentially warms up it will run and restart just fine all day. The engine RPMs will randomly fluctuate from 1500 to 3000 (One or the other) throughout the day.

 

[Babin Farms]

@84rzv500r probably will be more help than me with this issue. I'm sure he'll chime in on this.

 

[kjr6306]

Thanks for the input. Thinking the TPS is not working correctly but from what I can see the TPS voltage is within spec and matches my other engine. Also, cant figure out how putting the engine in the water prevents the engine from staring unless it's the extra load on the impeller vs. running on the hose on the trailer.

 

[84rzv500r]

sounds like maybe two problems... Maybe a lean condition... so sucking air in the intake system after the throttle plates... the carb cleaner check should help there... the servo and the ECU control no wake mode... when No Wake mode is selected the ECU commands the servo to open allowing more air to bypass the throttle plates through that mess of air lines and increases the pulse width to the injectors to maintain the desired air/fuel ratio and closes the control loop with RPM... did you run the servo motor test? BTW the servo motors run HOT... you could swap the servos side to side and see if the problem follows the servo... also the injectors could damaged from water ingestion...

 

[kjr6306]

Thanks. I'm thinking about just swapping the entire TB assembly to the other engine and seeing if the issue follows. If so, I will then just purchase a new assembly. My no wake does not work. I just chalked that up to me not rigging the throttle cable correctly but the service manual doesn't really give any specifics on the cable installation. Just says slack if I recall correctly. I did run the servo test and it seems to run correctly. I can hear the clicks. When you say they run "hot", what do you mean? Also, what is the purpose of the servo? Does this allow the ecu to control the idle?

 

[84rzv500r]

if this is a MR-1 engine then there is no way for the ECU to actuate the throttle plates so they use a Bypass Servo valve "when No Wake mode is selected the ECU commands the servo to open allowing more air to bypass the throttle plates through that mess of air lines and increases the pulse width to the injectors to maintain the desired air/fuel ratio and closes the control loop with RPM... " this is a very basic FI system the idle is not actively controlled it is adjusted via the throttle idle stop screw. There is no IAC like on the cars though the Bypass servo does basically the same thing however it is not in the normal control loop. (the no wake mode in boats and off throttle steering system in the skis is control is basically the same mechanism).
they are HOT to the touch and it does not mean bad... @Robb235 is another member who has intimate knowledge of these MR-1 engine controls...

 

[kjr6306]

Thanks for the input. It's helping me understand how the FI system works. It is an MR1 engine. Just to clarify, the bypass servo only has an impact on the idle when the no-wake mode is engaged. That would take the bypass valve out of the loop for troubleshooting purposes. One other point to note is that when I reinstalled the engine, I could not get the engine to start. After checking YDS, I noticed that the throttle valve opening was 0 degrees even though I had not touched the idle stop screw. After checking my running engine I increased the stop screw to increase the valve opening to 1.5 degrees to match the good engine. The engine then would start but it took an advance to 3.5 degrees for the engine to idle at 1550 RPM.....essentially had to add more air to the engine to get it to idle properly. Not sure if this is a hint as to what my issue is. Does anyone recall what their throttle degree opening is at idle?

 

[84rzv500r]

you do it by TPS voltage.... the throttle opening is a Calculated value and it is approximate...

there is a section in this link that discuss this in detail https://jetboaters.net/threads/repower-2004-ar210-with-mr-1-hos.35853/

 

[kjr6306]

Right. The TPS takes the mechanical position of the butterflies and converts that to a voltage probably via a variable resistor. Pretty straightforward. I can't understand why I needed to make that large of an adjustment just to get the engine to start and idle. And why the engine will idle cold on the trailer but as soon as you put the engine in the water I need to increase the idle screw just to get the engine to start.