200hp HPDI engine steam, and miss

[SJCJACKST]

Not yet. Having a hell of a time finding a way to haul it out...short of driving the boat up the Pacific coast about 30 miles to a boat launch near the Authorized Yamaha Dealer in my area. .... Which is probably going to be the final straw, since I cant even get a local tech to stop at my dock to run any diagnostics (which I was hoping for all along....). Another mechanic about 80 miles down the coast suggested I start changing out filters, and cleaning all of the injectors....

Also started considering if I should throw new plugs in, while I'm at it. I already have the new WP kits in hand (once I get the LUs off...)
SJC

[pstephens46]

You gotta find a way to get that boat out of the water. To get this thing resolved.

[pstephens46]

You could put plugs in but wouldn't fix the bubbles and steam.

[SJCJACKST]

Right....I am also trying to fix the miss/stumble issue at 800-1000 rpm on the same engine....

[pstephens46]

Where is this OP?

[pstephens46]

Good video. Cool that you popped it into gear too.

[SJCJACKST]

Well, thanks for checking in.

I changed spark plugs (to dual electrode NGK) and the miss seems to have improved. Since it continues to run good (took the boat out and ran down the coast about 10 mlles at 30 kts and back) without a problem, decided to wait until this fall to pull the boat out, replace the water pump kits, and paint the bottom........

Still steams and bubbles, though....
Thanks...

[Operaman]

I will post a larger pic so hopefully Rodbolt will have a look and respond on the spark plugs.

I was wondering if the plugs show signs of burning water.

These to me look like steam cleaned plugs, burning water. Cleaned up places on the plug.

Thoughts?

[SJCJACKST]

I suppose its possible....to me, its mainly "two stroke oily" in appearance. For what its worth, all compression levels are spot on...

But, as I said, I changed plugs anyway.

Again with the steam, and exhaust bubbles.................

SJC

[SJCJACKST]

Update,6 months later: Port engine STEAM ISSUE has (potentially) been resolved. Took some advice, and (1) tilted the engine full up (2) removed the thermostats and thermostat housings (3) poured about 2 cups of full strength SALTAWAY in each bank (4) replaced the thermostats (5) let the engine sit for 1 week (occasionally flopping left to right for good measure. Dropped the engines back in the water and started............no steam.... I'm an engineer, but not familiar with the cooling jacket on the HPDI, but something somewhere was cleansed and the steam went away.........a miracle.

Unfortunately, the engine still has the miss/stumble at round 1000 rpm (when putting out of the marina).....and the plugs still look like crap when pulled. Sigh.

Thanks yet one more time to all of the above advice from you gents...

[rodbolt17]

but no testing of plug caps,rail pressures on both the medium and HP systems> did you check the intergrity of the lift pumps?
did you carefully check the oil pump linkage and the link arm for freedom of motion?
I had two Z200 obe a z model the other a B model. both had a locked up oil pump.
one has 0 compression on 6 the other may have survived.

[pstephens46]

Regarding the steam/bubbles...There was a guy on another forum with a Z300. Same issue. I caught up with him a few months ago and said he had a stuck pressure relief valve. So if the steam and bubbles return, check that PRV. Rodbolt should be able to help with the miss.

[SJCJACKST]

Rodbolt,
plug wires and caps "look" ok. Have not tested Injector rail or injectors, no. However, recent YDS diagnostic results are as follows: All Codes 13-28 NORMAL.

At 650 rpm, Fuel Pressure 4.53 MPa, Fuel Pressure 662.76 psi, Ignition timing 3 deg BTDC, O2 Sensor Voltage 0.7 Volts, TPS voltage 0.55V, Throttle Valve opening 1.0 degree, Fuel Injection duration 1.11ms, Cylinders Firing: #1 Yes, #2 No, #3 No, #4 Yes, #5 Yes, #6, Yes (so 4 of the 6 firing)

At 1625 rpm: Fuel Pressure 4.84 MPa, Fuel Pressure 701.62psi, Ignition Timing 11deg BTDC, O2 Sensor Voltage 0.68V, TPS voltage 0.83V, Throttle Valve opening 7.0 degree. Fuel Injection duration 1.06ms,
Cylinder Firing #1 Yes, #2 No, #3 No, #4 Yes, #5 No, #6 No.

Frankly, ............all of these readings are very similar on the Starboard motor. Although I don't understand (for both engines) the Firing status. I know that the HPDI motors "cut out" cylinders during IDLE.

Have also replaced the low pressure Fuel Pumps recently. No affect. I suspect the Injectors may need cleaning, of course. Have not (but will) check the Oil Pump Linkage per your suggestion.

That (and the apparent clean up of the steam issue) is the latest.

Comments (and again, thanks very much)?

[rodbolt17]

can you post the model number?
the Z200 went through some changes in 04.
but your TPS and O2 sensor voltages are off and either your testing in N (worthless) or the shift position switch is not working.

[SJCJACKST]

Model # 6K1-LZ200XP. 1999 MY engines, I believe, thanks.. According to my YDS printout, the normal range for O2 is 0-1.0 volts, and TPS 0.5-4.5 volts.