J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Grey smoke won't idle...

Due to a 2600 mile move, new job demands, and other excuses I have not sailed me J/30 in about 8 months. I have been faithfully running the engine every 3 weeks for about 20 minutes. (battery charge and just running the thing)

It has been progressively harder to start with the start position of the throttle being more and more forward. When running the engine I have been running the RPM high before shut down to try and keep the injectors clean. This weekend the engine just died when I put it in idle. I restarted and ran the the RPMs above 2500 and I got a lot of grey smoke.

Any ideas?

I am thinking injectors. I am a diesel engine novice and had a few questions.

How tough is this job?
What is recommended for cleaning the injectors?
Will an additive fix the problem?
Will I need to bleed the system after cleaning?

Thanks!

Do you have treatment in the diesel? After 8 months your diesel tank is going to be a bacterial colony complete with skyscrapers, city parks and government funded health care.

Try adding some fresh diesel with treatment in it first.

I have owned for over a year and we are still on the first tank of diesel (still a half tank left...)

What kind of treatment do you recommend?

Oooof. Just go to your local auto parts store and look for some heavy duty diesel treatment that inhibits growth. I don't have any recommendations on brand.

After the treatment kills the growth, you are pretty much garaunteed to plug the filters next; if you don't have a primary fuel filter, now is the time to install one. You'll need to be changing it after this.

You may want to consider disposing of that half tank of diesel and scrubbing the tank which is by no means an easy and clean job. You might get away without doing it.

Diesel is an organic fuel and does not keep. You probably want to be burning through all the diesel in the tank every month. Try and get rid of that last half tank either by disposing or running it through and then get a few litres of fresh in there to burn through regularily.

I've gone the treatment root, recycled the fuel and replaced fuel filters in the past. I don't recommend that approach. The filters are more expensive than the fuel you are trying to save. Pump the tank dry, and if you can remove the inspection cover (some tanks don't have this), reach in and clean the junk out of the bottom of the tank. I learned this weekend that Mark Rotsky (Nemesis) uses an oil change vacuum pump to reach in and suck out as much stuff as he can. He does this every year.

Once clean fuel is added, do add the diesel fuel treatment and water absorber to prevent growth.

The fuel injectors can be pop tested by a diesel mechanic to check for proper spray pattern. A clogged injector will exhibit smoky exhaust and rough idle. I had the diesel mechanic at Oldport Marine in Newport, RI pop test, replace tips and shim my injectors for $80. It fixed a rough idle problem.

Thanks for the advice. I pulled both injectors. They both had a slight circle of soot on the face. I lightly cleaned them with a wire brush and re-installed.

I will remove the inspection cover of the tank, remove the fuel, and clean out the tank. I am an emergency helicopter pilot and work a week on/off. I am just starting back today but will let you know what I find.

Thanks again.

Okay time for an update:

Pulled the igniters and cleaned them.

Drained all of the fuel.

Cleaned out the fuel tank (thanks girlfriend Michele-small arms)
and all filters.

I tried to start the engine. It starts for a second and then dies..

I tried the first step of bleeding the system but I pump away with the primer level but never get fuel to exit out of the bleeder bolt. Any helpful technics on bleeding the fuel system??

Thanks.

You are air bound in the fuel system. Here is a 2 person priming tip that uses the fuel lift pump driven by the starter. I assume that all of your hose connections between the fuel tank, Racor filter and fuel lift pump are good and tight so no air can get sucked in. I also assume that your hoses have not aged and become hard or brittle. If you have connections that have stretched and are loose over the fittings, cut them back and make a new hose connection.

If you removed any of the steel fuel hoses in the fuel pump section, make sure you replace the copper washers on the banjo fittings. Make the connections tight, but don't over torque them. The copper washer compress and make the air tight connection.

1. Take the belt off the water pump - you will be turning the engine over with the starter and you don't want to fill the exhaust with water without the engine running.

2. Open the compression relief levers on the top of the engine.

3. Have some turn over the engine with the starter as you bleed each section. Start at the Racor filter. Since the fuel lift pump is drawing a vacuum on the filter, don't open any bleed connections there. Just turn the engine over for about 30 seconds to force fuel through the filter.

4. Next move upstream. With the the engine turning, hold a rag over the 2 micron fuel filter bleed screw after the fuel lift pump and crack open the bleed screw. Close the screw when you get solid fuel without any air bubbles.

5. The next area to bleed is the High Pressure fuel pump with the bleed screw on the inlet side only. There no need to bleed the high pressure side.

6. Put the belt back on the water pump, close the compression reliefs, and start your engine.

See this old thread for a comprehensive bleeding procedure.

Argggg...

I followed all steps above but could not get the filter to bleed.

I installed a primer bulb downstream of the large fuel filter. It pressurized the system and I bled the filter and the low pressure (inlet) side of the injector pump.

I started it up and it ran for a few minutes at 800-1000 RPM. It sputtered a few times but caught itself. I then accelerated it up to 2800 RPM and it slowly died like it was running out of fuel. I restarted but had the original problem of starting and slowly dying.

I have checked all of the lines for leaks??? Next step lift pump?

Thanks.

Ok - if your Racor filter isn't plugged I would suspect the fuel lift pump. Did you leave the squeeze bulb permanently installed? If so, can you keep the engine running by squeezing the bulb periodically? That would be a dead giveaway that you are fuel starved, probably the lift pump.