2001 Yamaha 200hp hpdi stalls, no power

[Pacill]

Have a 2001 Yamaha hpdi with 500 hrs. C Motor idles but as soon as I advance the throttle it misses and stalls. Some history. Had old gas in the tanks (almost 200). Added fuel stabilizer, pulled about 5 gallons of water out of the tanks. removed about 25 gallons of gas and replaced it with fresh gas. ran the gas thru a 2 micron filter. put the removed gas into my old jeep and it ran fine. I bought the motors used so I had to perform much maintenance so I would have a good starting point.
1 Changed the fuel lines from the tank.
2 Installed new 2 micron filters.
3 New low pressure pumps.
4 New fuel filters under cowling.
5 New vst electric pump and filter.
6 New metal hi pressure strainer filter.
6 Had injectors RX in Texas rebuild the hi pressure pumps and clean and test the injectors.
7 Cleaned the oxygen sensors.
8 New water pumps.

Hooked up Yamaha Diagnostic program and find no faults.

Motors run better on the hose than when in the water. starboard engine runs up to 29 hundred while the port stalls when I give it gas. I think the starboard. engine is maxing out at 29 hundred due to taking the whole load of pushing the GW Sportbtidge 25' boat. Any help?

 

[99yam40]

dump the old bad fuel and clean the tank and the rest of the fuel system.

cleaning things and continued running bad fuel just mucks it all up again

 

[Pacill]

Just checked all the coils with a ohmmeter. no specs for the 2001 hpdi for ohms but all read the same so that seems to be good. Tested the TPS and found it in specs. Checked the pulser coil for ground, no issues.
Hey Rodbolt how about some help for a OLD OMC service tech from NJ. I'm a points plugs and condenser man and old power packs at best!

Filters were replaced, hi pressure . Just did a static test on each coil and all fire as per my Stevens peak reading meter. Ran engine again on external tank with vinyl hose, no bubbles. Compression is 115/120 on all cylinder's. Pressures were at 50lbs. steady re; mid range electric pump, 685/710 hi pressure pump. Have an inductive tachometer (OMC) will put it on again. Had it in gear and two cylinders were down this time. according to the computer. They do kick in and I have to stay with the throttle because when they do it will scream. No I haven't switched the Shift position switch yet, I did unplug it and put a meter on it and when I put it in gear and neutral or toggle it by hand it does make and break. Do you think it could still be bad, intermittent issue?​

frustrated with this working on it for weeks and only slight improvement. That being it will stay running now but not good. Didn't get to test it in the water with my computer due to bad weather.​

 

[99yam40]

Rodbolt has not been here in years,
but if you do a web search for Rodbolt17, it should lead you to where you can find him on another forum.
make sure you post your complete motor model # when you post
there should be a shift cut switch and a switch to tell the ECU the motor is in neutral
make sure you are monitoring the correct on that cuts cylinders while in neutral

 

[Pacill]

Thanks, Model is LZ200TXRZ. I know about the Shift position sensor at the shift cable connection but it looks like you are talking about two different switches? Can you explain please. I can o to Boats.net and look at the parts diagram if you give me a heads up. Thanks.

 

[99yam40]

I have never worked on one of those motors, but have read stuff.
there is a shift cut switch on most larger outboards to miss fire some cylinders to allow the lower unit to come out of gear easier when shifting from in gear to out of gear/neutral .
there is also a switch to tell the ECU the motor is in neutral so it will drop some cylinders from firing, and drop more cylinders if the RPM is raised while still in neutral