Port engine won't start [Solved and Fixed]

[dgfreeze]

I'd recommend testing the switch itself first. Digital voltmeter, OHM test should tell you if the switch is opening and closing.

 

[ripler]

It seems that way. I think I found where the engine stop lanyard switch wires trace back to the engine but everything looks good. Frankly the wiring diagram I posted isn't that helpful but I'm not used to looking at them.

What you posted is the wiring for the dash. you need to look at the wiring diagram labeled "starting system", it will look like the one I posted. The lanyard switch will be labeled engine stop switch on the diagram.

The terminology in the YDS might be confusing as far as what means "on", it could be that the switch contact is closed and the switch is "on" or it can mean the switch contact isn't closed and the safety is "on". On the engine that is working fine and the lanyard is in does the YDS say it's off or on? The reason I'm saying this if "on" means the switch is made then the engine should be starting.

Here are the wires that you need to look at.

 

[jetboater4life]

I'd recommend testing the switch itself first. Digital voltmeter, OHM test should tell you if the switch is opening and closing.

I tested the lanyard push/pull switch and both circuits are functioning correctly. Open (no current) when no lanyard and closed (current flows/continuity) with lanyard present. Both behave the same. Swapping them didn't change anything either. In YDS, for the YDS "Engine stop lanyard switch" setting, ON means no lanyard present and no spark to spark plugs. OFF means lanyard is present along with spark. This worked great when plugged into the starboard engine. The port engine has it stuck ON no matter what I do with the switches.

 

[meaningreen]

Does the engine crank at all, or nothing happens? It happens to me every time I go out (cold engine) that one engine won't even crank, I move the throttle to full then to full reverse and back to neutral and then it starts. I haven't started trying to figure it out yet, I think there is a neutral switch somewhere. But my issue is turn key and no crank, nothing, I couldn't get from your posts if you were getting it to crank over and just not fire.

 

[itsdgm]

try swapping out the cleanout hatch switch/wiring connections.

 

[jetboater4life]

Does the engine crank at all, or nothing happens? It happens to me every time I go out (cold engine) that one engine won't even crank, I move the throttle to full then to full reverse and back to neutral and then it starts. I haven't started trying to figure it out yet, I think there is a neutral switch somewhere. But my issue is turn key and no crank, nothing, I couldn't get from your posts if you were getting it to crank over and just not fire.

My situation is simple. Both engines turn over. Starboard engine instantly fires up. Port engine turns over but does not start. I checked the plugs and it is not getting spark. YDS (Yamaha Diagnostic Software) says the Engine Stop lanyard switch is stuck on no matter what I do to the switch. The switch is good. The problem is somewhere on the engine side.

 

[jetboater4life]

try swapping out the cleanout hatch switch/wiring connections.

I don't think that will work since when I open the hatch neither engine will even turn over. Do you think it still could be related somehow?

 

[ripler]

I tested the lanyard push/pull switch and both circuits are functioning correctly. Open (no current) when no lanyard and closed (current) with lanyard present. Both behave the same. Swapping them didn't change anything either. In YDS, for the YDS "Engine stop lanyard switch" setting, ON means no lanyard present and no spark to spark plugs. OFF means lanyard is present along with spark. This worked great when plugged into the starboard engine. The port engine has it stuck ON no matter what I do with the switches.

OK this is what I thought, this means the ECU isn't seeing the switch being closed. One of the wires that I highlighted above is the issue and it should be easy to figure out which one. The lanyard goes into the ECU which is why you can see the lanyard status in the ECU. The cleam out hatch switches do not go into the ECU, so the ECU has no idea if they are closed or open, so you will not get a status for the hatch switches. The hatch switches are hard wired in series with the neutral switch and the key.

The engine hatch switches have 2 positions, one position on the switch proves the hatch is open and won't allow the engine to start, the other position proves the hatch is closed and allows the engine to start.

 

[dgfreeze]

I don't think that will work since when I open the hatch neither engine will even turn over. Do you think it still could be related somehow?

The cleanout hatch has two circuits, one prevents cranking, the other kills spark. One or the other can go bad independently of the other half. **If** the YDS doesn't distinguish the difference between the lanyard switch and the cleanout switch, I'd consider it a possibility. I haven't inspected the wiring diagram above, but tracing the wires to and from the lanyard switch should tell you if they're in the same circuit.

 

[the MfM]

Im assuming you have physically disconnected/swapped/jumped the lanyard wiring connections?


If the switch and wires checked out maybe it’s an ecm/software problem? If all else fails disconnect the battery and see if it resets.

 

[jetboater4life]

The cleanout hatch has two circuits, one prevents cranking, the other kills spark. One or the other can go bad independently of the other half. **If** the YDS doesn't distinguish the difference between the lanyard switch and the cleanout switch, I'd consider it a possibility. I haven't inspected the wiring diagram above, but tracing the wires to and from the lanyard switch should tell you if they're in the same circuit.

I was not aware of this. I thought it only killed the starters. I can inspect those circuits.

 

[ripler]

The cleanout hatch has two circuits, one prevents cranking, the other kills spark. One or the other can go bad independently of the other half. **If** the YDS doesn't distinguish the difference between the lanyard switch and the cleanout switch, I'd consider it a possibility. I haven't inspected the wiring diagram above, but tracing the wires to and from the lanyard switch should tell you if they're in the same circuit.

The ECU has no idea of the status of the cleanout switch, the ECU only looks at the lanyard switch.

 

[jetboater4life]

Im assuming you have physically disconnected/swapped/jumped the lanyard wiring connections?

If the switch and wires checked out maybe it’s an ecm/software problem? If all else fails disconnect the battery and see if it resets.

Yes I have physically swapped the lanyard wiring connections and the connections in the dash for the ignition.

 

[jetboater4life]

This is the correct wiring diagram. Now I need to start tracing.

 

[84rzv500r]

ok this seems to be a common problem... what does YDS say about the TPS sensor? does it read 0.747V at idle throttle with or without the engine running?
let me see if i can find the thread... there seem to be two failure mode where the TPS is out of spec but the engine runs rough and dumps too much fuel in the cylinders and if it is too far out of spec it will crank and fire the injectors bit not let the spark juice loose LOL...

 

[84rzv500r]

MR-1 TPS discussion

 

[Sbrown]

This is the correct wiring diagram. Now I need to start tracing. View attachment 181092

I don't believe that is the diagram you need. All that is for is the cranking circuits, not the run circuits. You said it cranks fine, but won't run. You need the actual run diagram. It'll probably have the injectors and coils on it as well as the ignition switch and the safety kill switch. Or I could be completely wrong and don't know my kill switch from my starter relay.

 

[jetboater4life]

ok this seems to be a common problem... what does YDS say about the TPS sensor? does it read 0.747V at idle throttle with or without the engine running?
let me see if i can find the thread... there seem to be two failure mode where the TPS is out of spec but the engine runs rough and dumps too much fuel in the cylinders and if it is too far out of spec it will crank and fire the injectors bit not let the spark juice loose LOL...

I believe the TPS was in spec but will double check the next chance I get. Probably Saturday morning. I was concerned about the engine oil increasing as that is usually a sign of gas in the oil but I did not smell any and removed some so that now the oil level cold is halfway up the stick. I had no oil in the air filter.

 

[jetboater4life]

I don't believe that is the diagram you need. All that is for is the cranking circuits, not the run circuits. You said it cranks fine, but won't run. You need the actual run diagram. It'll probably have the injectors and coils on it as well as the ignition switch and the safety kill switch. Or I could be completely wrong and don't know my kill switch from my starter relay.

I think you are right. But maybe this one is correct. Need to trace the highlighted wires I think.

 

[buckbuck]

I am following your diagnostics closely, @jetboater4life
I have the same boat (just older). I can dig up the service manual if you need any more schematics.