Hiva Oa Passage Day 3: Engine Trouble

Summary: Yesterday’s wind was short-lived, and we’re back to motoring with variable winds and side-to-side rolling conditions. But then our trusty engine puttered out just as we thought we’d soon see wind. Not surprisingly, progress is slower than we had hoped.
Position: 06 17.93 S 094 51.65 W at 22:30 UTC
COG: 241 degrees m
Distance : 142 nm (24 hr), 450 nm total
Average Speed 5.9 kts (24 hr)
Distance to go to Hiva Oa: 2,649 nm
The winds disappeared once again yesterday afternoon around 3 pm and we returned to motoring when our speed dropped to 2.5 kts with variable wind direction and speed. Later we tried to take advantage of slight SW winds by heading more south. So far the PredictWind forecasts (PWG and PWE in particular) have not borne much resemblance to actual conditions encountered. Wind direction has often been 90-180 degree difference and speed completely variable. Based on forecasts we thought we would catch better winds by this morning, but the calm zone seems to be moving along with us. The latest forecast again shows the calm winds tracking along with us and we’re getting a little bummed out.
At least that’s what I thought at 12:45 pm when the engine RPMs started surging up and down. A quick check of the Racor fuel filter bowls and vacuum gauge didn’t reveal anything wrong. Our next suspect was the engine fuel filter. A quick check with the aux fuel pump indicated restricted flow through the engine primary filter. We dug into the spare parts inventory and replaced both the primary and secondary filters with new ones. For good measure we ran the aux pump again to prime the system and noted a definite difference in flow rate between the old and the new. Low and behold the engine started up and ran once again. We are relieved to get back to reading, resting, and apparently not schoolwork. We managed to sail 14 nm in 3.5 hours during the repair with very light winds (attempted spinnaker was too floppy with the rollers).
We hope there wasn’t any issue related to heat or run time and shall see again soon if the winds remain stalled, but for now we’re enjoying some peace and quiet while we scour over the latest forecasts for our next move.
Wildlife Sightings: Seabirds and two flying fish on deck.