Thoughts on Engine Issue

[Jcolman]

My boat has a nearly new Perkins diesel. I recently had the filters and oil changed, the fuel tank cleaned and fresh batteries installed. Ever since I had all this work done, the motor fires right up and runs fine.

However, after spending 6 hours today, pounding close hauled into 20 knot winds on the Chesapeake, and bouncing around a lot, I went to start the motor and it wouldn't start. It seemed like it was about to catch, but it didn't. I tried at least 15-20 times, before it finally caught and fired up. From then on, it ran fine. At the dock tonight it fires up fine.

Any thoughts as to what the issue could be?

[sandy stone]

If you were cranking the motor while closehauled and bouncing around in 20 knots, depending on the level in your fuel tank you might have picked up a little air.
Also, if you crank the motor 15 or 20 times without it catching you might think about closing the raw water intake until it fires.

[Jcolman]

Thanks Sandy. What does closing the raw water intake do to help starting?

[SkiprJohn]

Sandy has suggested you close the seacock or valve that allows seawater into your cooling system. If you crank the engine quite a lot before it fires it may pump saltwater into your exhaust system because the firing of the cylinders isn't pushing it out the stern.

If you do close the seacock then you must open it immediately after the engine fires and leave it open when the engine is running.

Good luck. Could be a lot of things that happened including your engine stop switch getting jiggled or a bit of air in the system. Hard to say. Hope it doesn't happen again.

[mikeguyver]

crank too long before firing can fill your exhaust with water and risk back flowing through an open exhaust valve into a cylinder for one thing

[jongleur]

Or, if cranking too long, open the drain
on your exhaust accumulator, often called
your muffler. Wait until no water is draining
out before trying to start again. Yes, you
can pump water back into the engine but
closing the intake, may wear out your
impeller or collapse hoses.

[Dauntlessny]

Originally Posted by SkiprJohn

Sandy has suggested you close the seacock or valve that allows seawater into your cooling system. If you crank the engine quite a lot before it fires it may pump saltwater into your exhaust system because the firing of the cylinders isn't pushing it out the stern.

If you do close the seacock then you must open it immediately after the engine fires and leave it open when the engine is running.

Good luck. Could be a lot of things that happened including your engine stop switch getting jiggled or a bit of air in the system. Hard to say. Hope it doesn't happen again.

Agree,BUT, it will happen again.

Something is clearly wrong and it;s either not getting enough fuel or it;s getting air in the system.

Were you feeding from one or two tanks?

[Neptune's Gear]

Motion can cause crap to block fuel pickups. Calms down, picked up rubbish is dropped, runs OK again. Fuel pressure check, or look in tanks 😊

Sent from my Nexus 7 using Cruisers Sailing Forum mobile app

[transmitterdan]

If you have a Racor filter inline between the fuel tank and the engine lift pump consider installing a vacuum gauge in place of the T-handle. Then you can easily spot when the engine is starved for fuel due to blockage in the tank. The vacuum gauge will spike up any time there is anything blocking the flow of fuel up to and including the filter element itself. If you don't have a Racor filter then you should consider installing one. Some people advocate having two filters for redundancy but just one will protect against gunk getting into the engine filter and lift pump

[Jcolman]

Originally Posted by SkiprJohn

Sandy has suggested you close the seacock or valve that allows seawater into your cooling system. If you crank the engine quite a lot before it fires it may pump saltwater into your exhaust system because the firing of the cylinders isn't pushing it out the stern.

If you do close the seacock then you must open it immediately after the engine fires and leave it open when the engine is running.

Good luck. Could be a lot of things that happened including your engine stop switch getting jiggled or a bit of air in the system. Hard to say. Hope it doesn't happen again.

Ahhh,,,that makes sense. Thanks!

[HappyMdRSailor]

If ya had the tank scrubbed out recently, and you had low fuel levels, it's most likely air induction from bouncing around as Sandy suggested...

It's EXTREMELY helpful to know the conditions and fuel level where this occurs... same thing goes with heel angle/pickup side/fuel level... My Morgan starves motorsailing port tack at 1/4 tank... This is the type of knowledge that can keep you out of dangerous situations...

[Jcolman]

Originally Posted by HappyMdRSailor

If ya had the tank scrubbed out recently, and you had low fuel levels, it's most likely air induction from bouncing around as Sandy suggested...

It's EXTREMELY helpful to know the conditions and fuel level where this occurs... same thing goes with heel angle/pickup side/fuel level... My Morgan starves motorsailing port tack at 1/4 tank... This is the type of knowledge that can keep you out of dangerous situations...

The tank was about 3/4 full.

[Jcolman]

Originally Posted by Neptune's Gear

Motion can cause crap to block fuel pickups. Calms down, picked up rubbish is dropped, runs OK again. Fuel pressure check, or look in tanks 😊

Sent from my Nexus 7 using Cruisers Sailing Forum mobile app

I had that problem before so that's why I had the tank cleaned prior to this trip

[Jcolman]

Originally Posted by Dauntlessny

Agree,BUT, it will happen again.

Something is clearly wrong and it;s either not getting enough fuel or it;s getting air in the system.

Were you feeding from one or two tanks?

Just one tank

[Badsanta]

Maybe the pickup tube is too short.