Yamaha 200 HPDI no power

Help Help!!!! I have checked these forums for a problem I am having with my Yamaha 200 HPDI and still haven't been able to resolve it not going to max rpm. It will not throttle up now, before if I turned off the key and let it sit for a few minutes and it would work fine and then slowly loose power not going past 3200 RPM. Now it will just not produce any power maxing out at 3200 and doesn't idle very good or start right off.
My boat has twin 200 HPDI's so parts are not a problem. I have changed every fuel filter with new ones, switched fuel line supplies, swapped the VST unit, the high pressure pump, TPS switch (setting to .62 volts), cleaned the grounds, checked every wiring plug for corrioson, switched the coil packs, ignition modules, cleaned the O2 sensor, switched the crank sensor, tested the shift switch and compared settings with the good motor. Charging system is 13.01 volts. I have also replaced all the spark plugs even though they were not that old.
I can say one thing, when I changed the high pressure fuel filter and serviced the O2 sensor the thing ran at 5600 rpm for an hour, thought all was good until I took the boat out the next day and same thing no power.
I have totally run out of idea's and things to check or change. Unfortunatly I am 1000 miles south of the US border in Baja and no one here has a computer to test this motor and most boat places haven't even seen a HPDI.
I am hoping I gave enough information and would appriciate any help, need to go fishing.

Re: Yamaha 200 HPDI no power

Baja Johnny here, I forgot to mention that when I do disconnect the TPS on the bad motor nothing changes. When I disconnect the TPS on the good motor this motor runs exactly like the bad motor.

Re: Yamaha 200 HPDI no power

ALL the sensors can be tested with a multimeter,some alligator clips and paper clips to insert in the connector from the backside of the connector.
most the test harnesess are interchangable with most of the OX66 stuff and some of the other two stroke stuff.
do you have acess to a service manual and a digital multimeter?

Re: Yamaha 200 HPDI no power

Hi there Mr. Rodbolt thanks, I do have a digital multimeter but I DO NOT have a service manual, it is a thousand miles north of me in the states. If I could figure out where all the sensors like the Intake Air Pressure Sensor, IAC Sensor and had the values it would be great. As mentioned before I have the other engine running top notch and unlimited parts to swap. I today pulled all the injectors and swapped them with new gaskets (packings) to see if a injector problem but not, good motor with the other injectors runs great. Still confused that when I unplug the TPS from the good motor it runs exactly like the one with the problem. I have swapped them and set them at .62 volts at idle. Almost like the .62 is not getting to the ECM but without a wiring diagram not sure how to trace it. Hope this gives you some new insight. Going crazy, been reading and reading the forum and trying everything but doesn't seem to be fuel like most motors but a situation where staying on the 4 cylinders at idle and not kicking in the other two.
Thanks and hope for more info.

Johnny with No Manual

Re: Yamaha 200 HPDI no power

Baja thought, is there supposed to be vacuum to the VST at idle or off Idle, I get no vacuum at the VST hoses all three of them. Just a thought.

John

Re: Yamaha 200 HPDI no power

quit hunting rabbits.
use your digital meter on an ac v setting and compare the TCI outputs at all 6 ign coils.
no IAC.
set the >TPS with idle stop screw completly backed off and all throttle shutters completely closed,
set TPS to about .56V then lock 5 of the shutters leaving the cam shutter screw loose.
adjust the idle stop screw until voltage is about .62.
the high pressure sensor located at the HP pump should read 2.8 to 3.2V(pink to black) at all engine speeds if its low look at hp rail pressure and medium pressure rail.
the baro sensor pink to black should read about 3.2 to 4.6V
if the tech has a diagnostic test lamp that can be used on the HPDI motor.
when you unplug the TPS idle is fixed high,timing is fixed at 7 degrees BTDC and top speed cannot be reached.
O2 sensor feedback is not used above about 1500 RPM.
iat sensor is only used for minor fuel corrections.
CTS is used during warmup for fuel and timing corrections.
make sure all the orange wire 5v reference voltages are correct.

Re: Yamaha 200 HPDI no power

Thanks for the values on the sensors, I will check them out and do the adjustment on the TPS as you instructed. Hopefully get back to you as fast as I can. I did read in one of your posts to make sure that the TPS gets 4.75 - 5.75 reference voltage all the time, tilting, and toggling the oil tank switch so will also put that on the list.
I am however little confused on what the TCI outputs on the ign. coil is done, my meter does do ac but not sure where I am supposed to probe.
Thanks again off I go with meter and hope in hand.

John

Re: Yamaha 200 HPDI no power

TCI is Transistor Controled Ignition.
12V is supplied anytime the key is on to the ign coil primary side.
ground path is through the transistors in the ECU.
when the transistor(electronic switch) opens current flow stops and a voltage is induced in the coil secondary windings.
you really need a peak reading type meter to see it but the AC V function will work to compare voltages.
oil system has nothing to do with the 5V reference.
any orange wire under the hood has 5V when the key is on.
oil transfer is 12V circuits.

Re: Yamaha 200 HPDI no power

Thanks Rodbolt for the info, I will give this a go hopefully tomorrow. Being down a 1000 miles from the US and internet a challange any info is so much appriceated. I will try my best with what I got and let you know my finding. Just a quick question if the good motor acts exactly like the bad motor when TPS is disconnected is that where I should be looking at?

Johnny on your INfo

Re: Yamaha 200 HPDI no power

anytime the ECU sees an out of range sensor except fuel pressure or O2, it reacts by locking base timing and fuel to 7 degrees BTDC and a fixed fuel map.
this will limit RPM and cause a high idle.
depending on what sensor failed top speed may or may not be reached.
your describing a classic low high pressure rail condition.
try to find a shop with a diagnostic test lamp,it will display a code at the problem RPM.

Re: Yamaha 200 HPDI no power

Unfortunatly closest shop that MAY have diagnostic tool is Cabo which is 3 hrs away. I will try my best and hoping buddy is bringing me a manual sometime next week. Thanks again.

Johnny a Trying

Re: Yamaha 200 HPDI no power

tell him to bring that 80 dollar test lamp.
also bring the medium fuel pressure clip,a CV boot clamp tool or the oerlicker clip kit from sierra.
also bring spare orings for the VST and a spare VST filter.
remember the only time the test lamp will flash a code is when the code is active.
a fuel rail test guage would be handy as well to test medium pressure rail.
if either the medium pressure goes low or the HP pump is bad then the results are exactly what you posted just before a piston detonates.

Re: Yamaha 200 HPDI no power

Rodbolt, still doing the tests and such on the motors. Got the TPS switch's set now as per instructions. I will have the next person I know coming down bring what you mentioned but it might be weeks, mean while still got coils and such to check. Keep you informed.
John

Re: Yamaha 200 HPDI no power

Robolt and all that have given me a hand with this 200 HPDI with no power. Well not sure what is what but the motor is running like a top for the last 2 full days of fishing. I am not really sure what fixed it but will post what I did last. While checking all the components for the correct voltages I discovered a blue plug, 4 wires, down underneath the shifting cables from the wiring coming in to the motor. I am not sure where this plug and wires go but the connections were totally green. I cut all the wires and soldered them, put dielectric grease and then heat shunk the connections. I also found that I could not get the bulb to go hard so reading other posts put the prime bulb before the Racor, pumps up fast now. Adjusted the TPS and tested the Shift indicator. Took the boat to the water for further tests when motor was running but the thing ran like a top. I am not sure what the real fix was but hoping all will be good now. Thanks all and because I still have yet to get a manual if anyone has an idea what the blue 4 wire plug does would appriecate the info.
Johnny Happy