Diesel Issues - 4JHE

[KandD]

I've had a heck of a time with my diesel... seems to always choke out on fuel. I moved the boat through the marina a few weeks ago and it died 4 times ion me. It'll fire back up, but then putter out. I'm running off a day-tank and I replaced the filters again today. I have been running it for 30-45 min about every two weeks lately and it works fine. I ran it in gear against the dock lines for about 30 min today, to see if it would die with strain on the engine, but seemed fine.

Towards the end though, I got some heavy vibrations if I tried to take it up to 3k RPM, but they are gone if in neutral or reverse... Any ideas? I need to get outta the slip tomorrow and into a different marina to haul out, I'll sail most of the trip, but should I put it off a day to figure out the vibrations?

Any ideas

 

[Vinny]

K-D,

First off, nothing is blocking the air intake by any chance. The filter on this engine is just a screen and someone may have changer it to a paper element or a piece of insulation might be hanging down and getting in the way of the air flow. So make sure that the engine is getting air.

That leaves only fuel of the three things you need for a diesel to run, air, fuel and compression.

Does it run better after you change the in line filter? Has the filter on the upper forward starboard side of the engine been changed? That is a 2 micron Yanmar filter. The lift pump on the engine may be bad or an air leak in the fuel line to the lift pump could be the problem as well. It doesn't take much of an air leak. Quick fix is put an electric 12v FRB-20 Walbro (12V, 33 gal/hr 2-4 psi Marine pump) at the day tank and directly to the nipple on the on engine filter. One line, no leaks. The key here is low pressure, high gallons per hour. If the problem continues after this it is possibly the injector pump which you do not want to hear about.

 

[KandD]

Thanks for the tips, the air filter is open (I checked that yesterday) and I changed out both filters. I've changed out the lower several times, I think there was also quite a bit of water in the bowl (at least the fuel was clearer then I thought it should be).

I realized I'm missing some hose clamps from when I installed the day tank, so it might be sucking in air that way.... I'll give those a try and we'll hope for the best from there.

I'm still a little concerned about the sudden vibrations, if it's the shaft/prop the vibrations should occur in reverse as well correct??

 

[Vinny]

Thanks for the tips, the air filter is open (I checked that yesterday) and I changed out both filters. I've changed out the lower several times, I think there was also quite a bit of water in the bowl (at least the fuel was clearer then I thought it should be).

I realized I'm missing some hose clamps from when I installed the day tank, so it might be sucking in air that way.... I'll give those a try and we'll hope for the best from there.

I'm still a little concerned about the sudden vibrations, if it's the shaft/prop the vibrations should occur in reverse as well correct??

Clean fuel is clear with a red tint. Dark fuel is probably dirty. How can you be getting water if you are drawing from a day tank? Water will cause the miss for sure.

Yes engine miss vibrations should be the same in both forward and reverse. No vibrations in reverse could be but are not limited to a starboard side loose or broken motor mount which could be causing the air leak to increase if it is caused by a slice in the line or loose fitting as the engine torques up.

 

[drjdubowsky]

4jhe engine hose

I have a Jeanneau 42 with the 4jhe engine. Recently came across a problem. Owned the boat for 3 years. In commissioning this year, we have found the tubing connecting the raw water intake to the water pump(impeller) has multiple tears in it. Tubing is clear with wire-reinforcement. We are now replacing the entire tubing on the engine. Anyone else have clear tubing on their engine?

 

[rpleblanc]

This may or may not help. I have a 40.5 with the Volvo engine, but had the same symptoms. After much tracing and checking all lines, I found a hairline crack in the brass elbow where the fuel line came out of the tank. I only was able to see this crack after removing the pickup tube from the tank. It must have been overtightened years ago, and finally cracked. It allowed just enough air in the line, mostly at idle or after sitting overnight.
Good luck

 

[Steve Dion]

Why would there be ANY water in the fuel from the day tank.

I would suggest that you change out your fuel line too. If this is contaminated you are going to have problems too. This would clear up any issues with cracked and/or contamiated fuel lines.

 

[KandD]

Thanks for the tips! I'm thinking it's an air leak... so I'll track those down.

 

[KandD]

so I put on some clamps and I think that solved the issue... moved the boat today and had to motor the whole way - 7 hours. No issues with boat motor! YAY!

 

[miguelgdelrey]

the hose that goes into the tank

I have had the same problem with mine. Check the little hose that goes into the tank, it has a fitting at the end with a mesh and since it rest on the floor of the tank it gets clogged with the "black stuff" really easy.