HPDI Starting issue-Relay?Harness/VST Pump?

[powdahbonz]

Two weeks ago...03z175txrb-on 20ft Outrage..backing down throttle from 4000rpm to headway speed at a bridge, alarm sounded, looked down blinking left bar other two solid. Immediately cut engine. Checked both main tank and remote tank-main was 2/3rds full, remote was between 1st/2nd lines. Re-started, started building up speed, got to 2500rpm, alarm sounded, backed down throttle to neutral. Same flashing left bar…which did go away. Limped to buddies dock. Checked float in remote tank, connections, cleared white filters on remote and main by blowing through them, reinstalled(since then I have replaced both white filters for main/remote tanks). Left dock to run it-no flashing bars-no alarms..it ran rough after this, bit of smoke but gone after 5-10 secs. It ran better once getting over 3500rpm. No issue rest of day or afterward. Following week, while initial smoke at start up, sounding richer, acceleration and speed was normal…heading out to bait spot-ran between 3700-4500rpm for 30 minutes plus-was out idling around bait spot and engine cut out. Would not restart..turning key, could not hear medium pressure pump in vst kicking on with key turn. After about 20 minutes, restarted. Does not cut out under load. This happened 4 more times during the day. Headed back to dock, couldn’t manage more than 4100rpm at 25kts with 4 guys, half tank of fuel, sounded like it was running on 4 or 5 cylinders. Next day, same symptoms happened 4-6 more times. By myself, was getting 4600rpm-30kts-In July getting 53-5400rpm at 38-39.6kts.



Took apart VST, found filter had some haze(after 30 hrs since I did inspection in June with fresh filter). After reinstall, idle was poor-surging from 300-500rpm but would stall in neutral. Pulled plugs, #6 was carbon heavy other 5 normal(plugs new in June-less than 30 hours on them). Moved #6 plug to #1 cylinder to see change. Idle was still poor..300-500 rpm but bouncing around would stall in idle. Had to put it in gear to leave slip-in reverse-stalled going back to neutral-rough motoring from slip, smoked a ton(assume from burning off powertune I put in cylinders) but once over 2500rpm, evened out- But maxed at 4700 and 31kts,,sounded like it was running off 4-5 cylinders and not hitting top end. Checked compression-125 on the nose all 6 cylinders..760 hours on motor. Put in new plug to replace the oddball...No more idle issue. Idle back at 500-600 and normal idle for an hpdi. I think they all sound rough at idle. Went for ride yesterday-about 30 minutes of running at 41-4600rpm, come to spot to stop grab a drink from cooler and idle for a few minutes, and motor dies in idle. Trying to restart, gauge shows 1 blinking solid far left and 3 flashing bars, then goes solid..supposedly indicating communication error for oil with ecm. When trying restart, do not hear fuel pump actuate. Symptom has happened multiple times. Does not show error codes on yds. When cranking, will not start after multiple attempts. Each time you cannot hear the audible sound of medium pressure fuel pump. Switching batteries and doing a reset from 1 to zero or battery 2 to zero, no change. After about 30-45 minutes, getting ready to call BoatUS, turned key heard pump sound and knew that it would start-turned key-started normally..vroom..like nothing. These symptoms have happened on fresh fuel in a portable temporary tank and off my main tank. Confident that fuel(89) in both sources is good(filtered through a water separating filter before entering tank) and tanks are good. On way back to slip, back up to 5300rpm maxxed and 38kts..breezy(10-15kts wind), full tank fuel, choppy, lots of boat traffic but no issue. And this was just after fail to start just 45 mins earlier. Get back to slip, tying up, idling fine and motor cuts out after about 2 minutes at dock. All through this no alarms. Attempt restart..3 flashing bars then solid on gauge, cranked but no start. No sound from fuel pump. Same as just an hour before.

I’ve changed the small oil filters, in both remote and main tank, cleaned all connections with CRC, VST cleaned 4 days ago, cleaned mild grime on VST filter, new gasket, pressure 45-50. High pressure between 695-721. Low pressure pumps done last July, less than 75 hours, mid canister too July2019. I am stumped and feeling like this is either a harness or sensor issue, relay to vst pump? Assuming if it was fuse related, would not be able to restart at all. Maybe the vst pump is overheating-and when cooled off, restarts? Motor has always had diet of ring free, yamalube, startron stabilizer for limiting water, regular checks on all water separator and various filters and all normal must do’s for hpdi life. Why would I get an error for oil without alarm only sometimes? Leads me towards switch, sensor issue.



Anyone have thoughts/experiences with this behavior?

 

[boscoe99]

I am having a difficult time of making heads or tales as to what is going on. Try to focus. You are providing TMI. Too much information.

A Yamaha tachometer will tell you something if you look and listen.

Far left bar is for over temperature. Blinks when the temperature is excessive. Should be shown above a thermometer. Normally that bar is solid.

Three bars are for the oil system. Should be shown above an oil pot.

Normally all three oil bars are solid. System OK. If the right hand bar disappears and the middle bar flashes that is saying that the remote oil tank in the boat is low. Nothing else happens. If the middle and right hand bars disappear and the left bar flashes that is telling you that the main engine mounted oil tank is low. The alarm should sound. The motor should go into RPM reduction mode.

All three oil status bars will blink if there is a voltage problem. Alarm will sound. Motor will go into RPM reduction mode.