First belated cruise of the season was abandoned today as the Westerbeke, that ran superbly all last season, refused to run well. Filters have been changed and rechecked for air leakd this afternoon.
If I run at between 1000 & 1500 rpm, no problem, sweet and steady. Between 1500 & 2500 rpm, after 15 to 20 minutes, revs become erratic, dropping 2 - 300 rpm then recovering a couple ot times before dropping to 0. On re-starting, difficultly maintaining anything over 1500 rpm. Any suggestions welcome please.
Alan Steward
MagnifiCat 30C # 144
Hi Alan, sounds like your engine is starving for fuel. Did you change the filter in your water separator? If you have a Racor filter there’s a filter inside. It’s the first filter in line from the diesel tank so it gets plugged up first.
Ron
Ron & Diane Schryver
“Alpha Waves” 1987 NS30U #393
Georgian Bay Midland ON
Hi Alan,
Bummer that you finally get on the water and Magnificat’s diesel starts acting up.
My (completely uneducated guess) is fuel supply – I wonder if the fuel pump is getting tired? Also, I belatedly found out that the lift pump itself (at least the Facet unit) has a filter at the bottom that could use cleaning / replacement. In my case I found when the low rev situation occurred I could at least temporarily restore the revs by briefly opening the bleeder valve on the injectors. Sort of wearing on the diaphragm leaning over the cockpit locker opening to reach the valve. Eventually would get right into the locker having rearranged the gear stored there to facilitate such access. ( A nervy move when you are single handling and still have springs on the cockpit locker lids!) But the ultimate culprit was the fuel pump. Haven’t had the problem since I started cleaning/replacing ALL the #$%^&*() filters in the line (with, of course, a new fuel pump).
Cheers,
Bill Baxter
Persistence NS30 #507
Still on the hard in Penetang pending sale closing (thanks, Covid-19!)
Hi Al,
As was suggested it sounds either like a fuel pump issue (check for a loose connection as recommended) or water in your fuel supply. I had an issue years ago with water in the fuel, and the engine problem you have sounds very similar. It was an easy fix.
Check the Racor Fuel Separator… mine is mounted on the engine compartment forward bulkhead on the port side. Clear container that probably appears pink inside. There should be a drain petcock at the bottom of the filter. When I had the issue I though the Racor looked fine being all pink… however, the plastic gets stained pink over the years and if it isn’t dark pink, you may be looking at water and not fuel. When I opened it up, there was a thin film of fuel floating at the very top and the rest was water. Once drained of the water it ran well again, but water kept getting in, so I would drain before the water got to high in the Racor…
Figured out that the water was getting into the diesel tank from the deck plate… the old gasket was dry and cracked, and I was washing down the deck frequently. Replaced the gasket, no more water getting into the fuel.
Hope this helps.
Peter Grabow
S/V CAKE WALK III
1987 30 Ultra 430
Jersey City, NJ
This sounds precisely like a fuel flow issue and matches our symptoms fairly closely.
When you open the throttle you pull more fuel (and crud) into the primary filter and I would eliminate that before moving back to the fuel pump.
Fuel filters rarely block completely and suddenly, they fail slowly and only when the fuel flow is reduced substantially does the engine start to get impacted. Frequently when we would shut down the release of pressure on the downstream side of the filter would allow some crud to drop off the filter and we could run for a while before re-occurrence.
https://charlie-alpha-tango.com/home/2020/1/1/fuel-cleanlines
Jim Denmark
C.A.T. 1982 30C #146
Lying in the hard in Oriental, NC
Check the fuel tank vent hose. It may be plugged by spiders… and that condition will cause exactly the symptoms you describe.
Good one, Thor. I had forgotten all about that. You are right on!!
Joe Valinoti
S/V iL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA