Skip to main content

Ask Sail: A Faltering Start

My Yanmar 3GM30F diesel engine has about 650 hours on it, and this season, it’s been a little hard to start it. Are injectors or compression the problem?

James Macallister of Toronto, Ontario, asks:

My Yanmar 3GM30F diesel engine has about 650 hours on it, and this season, it’s been a little hard to start it. I have to put the throttle at one quarter open before cranking, and once started, the engine surges between 1,000 and 2,000 rpm for about 30 seconds. I can then drop the throttle down to idle speed. Are injectors or compression the problem? There is no smoke at all, and the engine runs fine once it settles down. Restarting after a couple of hours of downtime requires no special procedure.

Nigel Calder replies:

This might be a compression problem. Cranking at quarter throttle will increase the initial fuel-injection rate, with the fuel in those cylinders that aren’t firing dribbling down onto the piston rings, raisingw the compression to the ignition point. However, once a cylinder fires, it typically kicks right in, and you would not see the erratic operation you describe, so I doubt this is the true cause.

It also doesn’t sound like an injector problem in that things run fine once you’re over the initial starting hump. Most likely air is finding its way into the injection system when the engine is idle, which is causing problems until it is driven out. Has the secondary filter recently been changed or the system bled? Check the filter seal, the bleed screw and the injection line connections. Finally, I’ve also seen this happen when the injector leak-off pipes somehow manage to siphon fuel out of the injection system, so check for that.

Got a question for our experts? Send it to sailmail@sailmagazine.com

Related

maintenance-02

Cruising: Old Sailors Never Die

“Old sailors never die, they just get a little dinghy.” It may be a hoary old joke, but one of my problems at age 79 is I can no longer get easily in and out of a little dinghy, and neither can my (several years younger than me) wife. For this, and various other reasons I will ...read more

01-LEAD-DSC_0953

The Mighty Compass

Here’s to the humble magnetic compass, without a doubt the sailor’s most reliable instrument onboard. It’s always there for you and with the rarest of exceptions, always operational. Yes, I love my chartplotter, autopilot, radar and AIS. They help me be a safer and more ...read more

02-En-route-Jost-Van-D

Chartering: Swan Song in the BVI

Joseph Conrad once wrote, “The sea never changes.” And while this may or not be true, something most definitely not open for debate is the fact we sailors, “wrapped in mystery,” as Conrad put it, are continually changing—whether we like it or not. I found myself thinking these ...read more

220307FP51_1JML0332

Boat Review: Fountaine-Pajot Aura 51

If you can sell more than 150 catamarans off-plan before the resin has even hit the fiberglass, you must be doing something right. Despite costing around $1.1 million once fitted out and on the water, Fountaine-Pajot’s new 51 has done just that. The French yard has been at it ...read more

00LEAD-IMG-9035

Ready to Fly a New Sail

It’s a typical humid, southern Chesapeake Bay summer day when I show up on the doorstep of Latell & Ailsworth Sailmakers in the one-stoplight, one-lane-roadway, rural tidewater town of Deltaville, Virginia. I’m late getting here to work on a new jib for my 29-foot, Bill ...read more

m5702_RACE-AREA-6

Dates for the 2024 America’s Cup Announced

Ever since making the controversial decision to hold the next America’s Cup in Barcelona, Spain, instead of in home waters, Defender Emirates Team New Zealand has been hard at work organizing logistics for the event.  The Racing Area for the Challenger Selection Series and the ...read more

00LEAD

A Force for Change: Captain Liz Gillooly

I first heard about Capt. Liz Gillooly in 2016 from my cousin while working three jobs in our shared hometown on the North Fork of Long Island and living with my parents to save money for a boat. But despite being the same age and growing up only 13 miles apart, Liz and I never ...read more

291726157_3222349914654950_8713674249134934221_n-2-1024x684

Sailing in the Growth Zone

The Goal This year, I’ve had a specific goal to be a better sailor. Some people have laughed and said, “Why do you need to be a better sailor? This was my 22nd year racing on the same boat, with the same crew. I like to win and want to make sure we stay at the top of the fleet. ...read more