Stumped running on 3 cylinders

[dawgslife5436]

UPDATED ABRIDGED VERSION FROM PREVIOUS POST. PLEASE HELP!!!

2000, HPDI, 200HP, 535 Hours. Just completed a rebuild, compression 120. ALL fuel filters are new. High pressure pump was sent out last year for service. Injectors too.

Symptoms: rough idle, slow throttle response, misfire/backfire, puff of blue smoke emits from exhaust in sync with misfire. White smoke when I rev it up. Found the upper LPFP was leaking. Replaced it. Still have white smoke. I did not have these symptoms prior to the rebuild. Engine is being run in a test tank in gear using the harness, oil tank, ignition switch & gauges.

Confirmed running spark on all 6 cylinders. When injector connectors or spark plug boots are pulled on cylinders 1,2 & 3, there is no change in the poor running condition. When 4,5 & 6 are pulled the engine stalls. Timing shows 4 btdc in neutral and TDC in gear at idle on YDS. No codes

Spark plug boots, coils, pulser coil, o2 sensor, injectors, tps (set to 61) all ohm to spec. Shift position checked out. Swapped injector 2 with 5. Same running results I unplug injectors or boots on 1,2 or 3. No corrosion on any connection or grounds.

Swapped out the injector driver and then the ecm. No Change! Pulled the STBD fuel rail with the injectors attached, cranked the motor and all the injectors had a great atomized spray pattern. Didn't pull the port side. Assumed #2 was spraying too. Checked flywheel, still in its keyed position. I have fuel compression and spark. What else can I check???

[99yam40]

cranking and running are different animals on the motor.

use proper test equipment would be my thought or take to a shop with the proper techs and equipment

[ausnoelm]

You say you have fuel, compression and spark?? now providing you do have all three (which I doubt) then all there is left is timing, and timing doesn't usually just "go" so, best bet is to find out which of the three you say you have got, is not what it is supposed to be.

[TownsendsFJR1300]

It would be EXTREMELY HELPFUL to keep it all on one thread so folks can see ALL you've done to it, recommendations, etc.

You have numerous reply's on the other thread:

http://www.yamahaoutboardparts.com/f...s-th27804.html

[cpostis]

First off, I may be way off on this, but you may want to check your O2 sensor.
You did say cylinder #1 spark plug was dry carbon black. This cylinder is where the O2 sensor gets it's sample. Your sensor and or joint to the sensor may be fouled. There is a tech bulletin O99-008 that I can send you if you PM me with your email address. The bulletin refers to OX66 engines. Whether or not it pertains to your HPDI, I do not know. Below is a excerpt from the bulletin.

Again, don't know if it will help or not. Others, please give your opinion.

[IMG]O2SernsorBulletin by Charles Postis, on Flickr[/IMG]

[cpostis]

First off, I may be way off on this, but you may want to check your O2 sensor.
You did say cylinder #1 spark plug was dry carbon black. This cylinder is where the O2 sensor gets it's sample. Your sensor and or joint to the sensor may be fouled. There is a tech bulletin O99-008 that I can send you if you PM me with your email address. The bulletin refers to OX66 engines. Whether or not it pertains to your HPDI, I do not know. Below is a excerpt from the bulletin.

Again, don't know if it will help or not. Others, please give your opinion.

[IMG]O2SernsorBulletin by Charles Postis, on Flickr[/IMG]

Sorry, I confused you with another OP about the bold text above. However, this still pertains to you

[cpostis]

Found the link to where you can access the bulletin I mention.
Yamaha Oxygen Sensor Information

[dawgslife5436]

Well, I can see the atomized fuel spraying out of the fuel injectors while cranking. If the injectors shut off after the engine starts, I have no way to check that. Compression is 120 on all cylinders. I pulled each spark plug one at a time, started the engine and while holding each spark plug with insulated pliers observed a strong spark. I'm aware the timing just doesn't go. Can't figure this out.

[dawgslife5436]

cptstis
thanks for the info. I will look into the o2 sensor.

[rodbolt17]

you do not have an O2 sensor failure.
that would affect all 6 not just 3.
you can check for an injector signal with a multimeter and some paper clips.
my timing light will trigger off the HPDI injector signal.
it is about 90v peak.
all tests must be done in gear with the ECU "seeing" the shift position switch OFF.
when cranking the ECU MUST "see" the shift position switch ON.

[dawgslife5436]

Thanks for the info Rodbolt17

I will check the injector signal. Any possibility it could be the crankshaft position sensor? I was going to check the harness today to see if any of the wires are damaged or worn. I didn't have this issue prior to the rebuild. Frustrating!

[rodbolt17]

if you had any sensor failure,other than O2, you would get a code on YDS.
YDS is a wonderful tool, however all it does is show what the ECU "sees".

it is up to the YDS operator to use the tool between his/her ears to interpet it.

myself I wuld test the spark Kv and the injector signal.
that motor is known to eat spark plugs.

any black laquer looking coating on the insulator scraps the plug.

[dawgslife5436]

I interpet the YDS as such. No codes. Good. All sensors indicate operating within Yamaha specs (near perfect) according to the engine monitor (running). Good. Seems simple to use. Stationary tests all good as well.

Just pulled the plugs again which are new. Plugs 1,3,& 5 are fouled; covered in black dry soot. plugs 2,4 & 6 are slightly wet but fairly clean not tan as they should be. Obviously a problem. Cold as hell here in NJ today. Didn't get much done on this today. At least I have til spring to figure it out. LOL Anymore thoughts?

[TownsendsFJR1300]

As cold as it is and running cold water, is it possible the engine NEVER warmed up fully? IE, rich plugs, thermostat not fully opened, etc?

With new plugs, it also generally takes a good run to get an accurate reading IF all is normal. (Just as you saw with your one plug too rich).

[rodbolt17]

sensors can give an in range failure.
no codes but the ECU reacts to a bad signal.

kinda like an F250 I did a while back.

no codes.
two other shops had worked on it.
I saw the problem on YDS without ever running the motor.

baro pressure at key on engine off was 19"Hg.