2006 200 HPDI - TPS Troubleshooting Help Needed

[murphy21]

Hello, new to the site... I have a 2006 200 HPDI VMAX that I am having issues with. Issue - Started boat up after sitting for 4 months. Surging terribly at idle in and out of gear and would not go above idle while in gear. Any throttle at all killed the engine immediately. Drained all old fuel, new fuel line from 10 micron to motor, new primer bulb, all new filters (except mystery filters), new plugs. Started with muffs in the driveway and began surging again but then turned into a high steady idle at 1500rpm (even with muffs it usually goes from 1000 cold to 750-850 hot). Engine was rough at 1500 assuming because of idling on 4 cyl. Put a spark checker on each cylinder and all worked as should in gear and neutral. Took breather cover off and moved throttle link bar and engine settled to 1200 but still sounded more rough that usual. In gear still would not rev over idle. Checked TPS and noticed voltage would go from .68v at idle to a lower number instead of increasing with throttle. Tapped into wires and cannot get a 5v supply power reading with any combo of the 3 wires.

Over the winter I pulled new cables in the gunnel for adding fish finders. Is there anything I could have pulled loose in the gunnel to start this issue? I am only assuming that all sensor voltage is supplied directly from the Yamaha side and not from within the boat?

Any help would be greatly appreciated.

[rodbolt17]

5V orange to black.
if you don't have it, find it.
could be a ground cable.
could be another sensor draining the 5v.
if you look at the harness diagram you will note the ground path and the 5v path have multiple connections.

[murphy21]

Thank you for the help rodbolt17.
I do not have a wiring diagram and couldn't find a copy online. Are all of the diagrams located in the Service Manual? If so I will try to find one to order.
I went around the motor last night after reading a different post of yours and looked at other 5v sensors and everything else has the 5v but it was pink to black. Did not cross orange and black on those.
On TPS last night I was getting zero on the pink to black and 1v showing on orange to black. This was on the engine side of the plug.
To your knowledge is there anything on the boat side of things that could cause this? Since I pulled transducer cables through the hull I keep thinking I pulled a ground or something loose but don't want to chase a ghost. Main battery ground from boat to motor looked fine.

[boscoe99]

[murphy21]

Thank you boscoe... Forgive my ignorance but I have a couple of questions if you have time.

- The orange junction block that contains 4 orange, 3 yellow, and 3 red/blacks. Is this a 5v supply distribution block and if so what are the yellow and red/blacks?
- It appeared last night that the pink ran directly to the ecu. Is pink the sensor reference back to the ecu? So it should be reading the .60+/-.02 at idle? (orange supply, pink reference to ecu, black ground?)
- What is the best manual I can buy that will give me full wiring diagrams?

[boscoe99]

Thank you boscoe... Forgive my ignorance but I have a couple of questions if you have time.

- The orange junction block that contains 4 orange, 3 yellow, and 3 red/blacks. Is this a 5v supply distribution block and if so what are the yellow and red/blacks?
- It appeared last night that the pink ran directly to the ecu. Is pink the sensor reference back to the ecu? So it should be reading the .60+/-.02 at idle? (orange supply, pink reference to ecu, black ground?)
- What is the best manual I can buy that will give me full wiring diagrams?

The 4 orange are common. 5 volt power supply from the ECU via one orange wire. The other three orange wires are the power to the three components on the left.

Yellow is key on battery power. ~ 12.7 volts. Higher when the motor is running of course.

Black/red are switched grounds. One from the remote oil tank switch, one to the tachometer and one to the ECU.

Pink is the voltage to the ECU. Voltage varies with the TPS opening or closing. Same with changes to the pressure sensors.

Yamaha manual is the one to buy. https://www.boats.net/product/yamaha...IT-18616-VZ-20

[murphy21]

Awesome information! Hopefully this will get me where I need to go. I will dig deeper this afternoon after work and will post my findings. Thank you guys!

[murphy21]

Rodbolt and boscoe... Can't thank you guys enough. I had added the Yamaha water pressure sensor kit a couple of years ago to get my water pressure digitally to my graphs through nmea. That sensor was shorted (assuming busted over the winter) and taking the power from the other 2 in the chain. Unplugged that and the TPS adjusted perfectly and away we go! Once again, many thanks!

[boscoe99]

Thanks for the feed back. Glad you found the problem. How old was the sensor? Early sensors were known to fail internally and drag the reference voltage down. Or cause other mayhem. They share the same 5 volt power supply.

Unfortunately Yamaha never updated the SM to reflect the water and pressure sensors that can be added as options.

[murphy21]

The sensor kit was purchased 2 years ago this month.

[boscoe99]

You should have received the updated sensors. They can still go bad however. As you have found out.

[murphy21]

It's gone for good. Going back to the tried and true analog gauge.

[Enki 4040]

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