Diesel engine won't start after changing fuel line

[B Tegge]

Do not bleed from the tank. Start at the discharge side of the fuel transfer pump. Work your way to the high pressure fuel lines at the nozzle end. The end at the cyl. head.

[Snore]

Been there, done that, had post air-leak therapy.

First, you have discovered why spending $50 on a diesel lift pump is the best move EVER. Turn key on and as long as the fitting upstream of the lift pump are good, easy to bleed.

Second, start by bleeding the engine and getting her running.

Third, while at the dock open a beer or make a TALL mixed drink. With the engine running at a fast idle enjoy your cocktail. If the engine stalls, you have a problem (see step 4). If after 25 minutes she is still running, you got off easy. Have another drink to celebrate.

4- well your in it now! There is an air leak somewhere. Logically, it is in the line you replaced. First remove and inspect each end of the hose you installed. Did the clamp damage the hose end? Second, make sure the clamp did not break. In the list of my OCD compulsions is I buy the “good” hose clamps that have a rounded edge, like a ring, vs the cheap ones.

5, check the hose on the either end of the fitting where your replacement hose ends. If the hose ends at the filter, check the old hose on the other side of the filter. Do the same type of check.

6- bleed engine (lift pump!), and repeat steps 2&3. If the engine still has an issue, check all the hoses.

7- bleed AGAIN, repeat 2&3.

7a- If there is still an issue- or you decide to say @##$up and take some time off the problem, bleed the engine and immediately stop it. Then place paper towels under fuel line and fittings. Hopefully, there will be a drop to indicate where the leak is.

[thunderhoof]

I have used a fuel line priming bulb for years between the Racor filter and the engine mounted lift pump. Great time saver after filter changes.
And yes, diesel- rated priming bulbs are available.

[txg]

Originally Posted by sailingfarmer

Diesel engines are designed to make owners swear and curse when they need to bleedan engine... the future designer of a NON-BLEEDING Diesel Engine will make a fortune... maybe some sort of fuel compressor that rids the lines automatically of air....?

Vetus M-Line engines have automatic bleeding due to an electric lift pump. Even with completely empty fuel lines and filters (after installing the new engine) there was no need to open any bleed screw. Just put the ignition key to on position, wait for a minute while listening to the alarm buzzer and then start the engine without any problems. Very good feature.

[Kokanee]

Yes- the Vetus M-line diesels are great with their electric fuel pump system.
I’ve even installed new fuel filters dry, turned on the key and the fuel pump primes the filters and lines in about 20 seconds without any fuss.

But every diesel engine has it’s own unique way of best bleeding the air from the lines. Learn it before leaving the marina on any new boat.

[stormalong]

Originally Posted by Stu Jackson

Look up Maine Sail's "Hall of Fail" post on his website and learn why manual fuel bulbs are a bad, bad, bad idea. I don't know why people with Yanmars just don't install fuel pumps and make their lives a lot easier, but we see it here all the time, and on other boating forums.

Good luck.

I can't find anything on Main Sail's site about squeeze bulbs. Please provide a link. Thanks.

[Stu Jackson]

Originally Posted by stormalong

I can't find anything on Main Sail's site about squeeze bulbs. Please provide a link. Thanks.

Sure:


https://marinehowto.com/hall-of-fail/


Didn't Hall of Fail help?

[GregoryK]

So came across this engine bleeding method. When I had a recent issue after changing my fuel filter, it worked rather well.

https://www.youtube.com/watch?v=f5qfEayHx8c

[NYSail]

Do not loosen every joint to bleed...... you will then have a possible issue with the copper crush washers. Read the manual and bleed from the bleed points Yanmar starts with secondary filter, injector pump then if that doesn’t do it head to the injectors. As was stated all engines are different...... read the book

Greg

[gaffie]

Originally Posted by sailingfarmer

Will someone please design a diesel that does not require bleeding?

They have

[stormalong]

Originally Posted by Stu Jackson

Sure:


https://marinehowto.com/hall-of-fail/


Didn't Hall of Fail help?

Interesting. I would like to know how 75 gallons leaked from a squeeze bulb on the suction side of a fuel system. Unless the squeeze bulb is below the tank. If mine were to split the vacuum would break, the fuel would flow back into the tank and the engine would stop.

[Lepke]

Originally Posted by sailingfarmer

Will someone please design a diesel that does not require bleeding?

Detroit Diesel, 2 cycle. Since the 1930s as Gray Marine. Mechanical injectors and no injector pump. The gear fuel pump circulates about a half gallon of fuel per minute or more depending on the model. Since the fuel constantly circulates, any air goes thru the engine and back to the tank and expelled there. While it's better to use an auxiliary pump on completely dry fuel fuel lines, the fuel pump has enough volume to quickly push the air out.

[a64pilot]

Originally Posted by sailingfarmer

Will someone please design a diesel that does not require bleeding?

There are many that self bleed, my Yanmar 4JHE does, of course it has to get fuel though, you do have to fill the filter.

The single cylinder Kubota on my Nexgen generator is self bleeding, all you do is energize the electric fuel pump for 30 sec or so and crank it up, the electric fuel pump bleeds it.

[OZ-Sailor]

Still unable to get the engine to start. I have tried bleeding the injectors and also at the Point where the fuel line meets the engine there is a hex head which I loosen and had diesel squirting out of it when turning the engine over

I’m having trouble determining the model of the motor. It has the letters B8 and number is 238 on the top of it but cannot find any information on this.

I IM unable to find any type of manual pump on the engine

[NYSail]

If you follow the fuel like back from the engine where the bleed screw is you should come to a fuel pump which should have a pump on it...

After bleeding at the hex nut (assume all fuel and no bubbles) go to the injectors in sequence and loosen fuel line in, bleed till no bubbles tighten then do the next one.

Again be carefully turning engine over as the engine could flood.....

Good luck
Greg