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.

My 2QM-15 will not start unless I bleed the high pressure side. It even says to do so in my manual. Crank the engine over with the decompression lever open and crack each injector return line at the injector.

Hey guys. Checked back on the board from a long hiatus and found my problem on the front page. My Yanmar;

1. Won't reach high RPM like she used to.

2. Starts to smoke a little with the exhaust after a few minutes.

I have diesel additive in but fuel's old and I've never cleaned the tank or any filter other than the big one in front of the engine.

Guess I got some maintenance to do.

BTW, if my boats been for sale for almost a year, I'm practically giving it away and it's not sold, I think that means I should keep her.

Bill, if I keep her I'm gonna pull the Yanmar and rebuild her. This would only be possible due to the work you spent on the write-up. Thanks.

Rob - I guess it's a mixed blessing for you, but I'm glad you will keep the boat! You've put a lot of work into restoring Mango Madness.

You should be able to rebuild the engine without any problem. You could even keep the boat in the water, disconnect the shaft coupling and winch the engine out if you wanted. I built an engine stand using 2x3 studs and recommend you get the engine on the stand in the boat immediately after pulling it off the mounts. It's easier to manage that way.

If you have a standard shaft seal, it's easy to keep the water out with the coupling disconnected and shaft slid back. It's also possible with a dripless seal, as I did that when I took the transmission out 3 years back. I just built a strongback and clamped it in place to hold the stainless collar against the carbon seating surface. Good luck!

Okay finally had a day off...

1. Fuel tank-clean
2. All filters-new
3. New fuel lift pump
4. New squeeze bulb primer
5. Bled small filter and low pressure side of fuel injector pump

I started the engin and kept the RPM at about 800 for 3 minutes to warm up (grey smoke comming out of exhaust and it feels like the throttle position is more forward than normal) As soon as I try and advance the throttle it dies.

I try and restart it just dies again.

My last step will be to replace the fuel injectors(?) but I am at a roadblock.

The silver lining is I am now VERY familar with the fuel system on a 2GM!

Don't buy new, take them to a diesel injector and injectorpump repair shop. Reworking injectors is a common repair.

Thanks!

Did you check for a blocked exhaust elbow yet? Could also be a blockage in the exhaust.

No I will add that to the list. Thanks.

I cleaned the injectors-I haven't check the spray pattern and check the exhaust elbow (it was in really good shape-just some soot)

The engine will start very quickly run for a few seconds and slowly die like it is out of fuel.

I thought I might have a blocked fuel line but the engine ran the same after I ran a new fuel line. I also removed the vent line so the tank was being vented from the fitting.

I installed the squeeze bulb between the large filter and the lift pump. Is this the right location for it?

I bled the high pressure side of the fuel injector pump but had the same results.

The only thing that I can think of is that the tube in the tank has become blocked or moved when we cleaned the tank. My next step will be to connect a plastic portable fuel can directly to the large fuel filter and see if that helps.

Any suggestions?

I am scared to admit this in this croud but I'm a diesel mechanic. Have you done a fuel flow test before and after the Injection pump? using the decompresion valve crank the engine over for 20 seconds. if you have good steady flow then check after the pump. if both injectors are getting steady shots of fuel then its the exaust. if you have fuel problems after the pump its an easy removal and get it rebuilt. they break springs and cause low injection pressures.

Sorry I missed your previous page. your right its starving for fuel due to an air bleed. when it dies take a fuel filter off. if it is empty then air is getting in. or you have pluged your filters. have you changed the primary on the engine? this is a common spot for an air bleed as people lose the copper washer or pinch the oring on the cup.
if you find it is air you can cheat the problem to find it by over presurising the fuel low press side and where the leak shows up is your probem. or you can put a piece of clear line on the fuel return and watch for bubles. it will stop when you find the problem.
and to help the priming I use a simple vacume pump for bleading brakes. I often end up doing this on many boats so It pays to be portable. using the simple cone on the end of the vacume line you suck the fuel up to the primary through the bleed port and then again on the HP feed to the injection pump. This will also allow you to see the bubles in the suction line if you have a bleed further up the line and saves the time on the starter. This vacume pump is cheeper than any electric lift pump.

then do the fuel flow test.

It's about time you registered here Don!

Yah I know I have been doing allot of organising here for my club and neglecting the core of the fun in the J30 fleet.
Check out my notes on the NW forum for races in our area.
you doing Saltspring and Swiftsure this year? and you should do N100

Don
When you say decompression valve do you mean for the combustion chamber? does that mean you could start the motor with no power by wraping a strap around the crank? My grandfather has an old tractor with decompression valves and you started it by turning the fly wheel by hand. Where is the valve located?

OK how do I post pictures here? ok got it. http://forums.hunter.sailboatowners...&attachmentid=28425&d=1264130610



ok wee hwo this works. the lever is next

http://forums.hunter.sailboatowners...&attachmentid=28426&d=1264131595

for the bleed procedure.

http://www.google.ca/imgres?imgurl=...s%3Disch:1&ei=mznoTMzaNYfmsQOmhPGwCw

that should show you where every thing is. Remember not to crank the engine too much with the water going as you can fill the engine with water if not properly drained in the exaust system. do this by taking the water pump belt off. but I have never needed this.

and dont crank it too much as you may over heat the starter and burn it or melt the conections on the starter. This is in extream casses.

hmm I would still prefer to post the actual image. how do you do that?

I have the original PDF for the engine and transmission.
I just do not know how to post them.

good info to have.

Many may not be aware that the Yanmar diesel has a bit of an archaic governor and you have to manually put it to full fuel (in neutral) to start it according to the book. this is because the governor springs push it back right away rather then use springs to push it to full fuel and weights to force it back to idle.

but hey its a good little motor and easy to work on and lasts forever so I will forgive them that small oversight.

do you have the QM, YM, or GM?

any way its on top at the front. its the lever on the valve cover. take some string and tie it back.
the engine will not start as long as it is pulled. as well put the engine to no fuel. just remember if bleeding you will need to put it to full fuel to bleed past the injection pump.

They may already be posted. On the J/30 menu at the top, mouse over "Info", "Articles of Interest", then click on "Diesel Engine Maintenance" - If you have a Yanmar manual that isn't there, please let me know.

Ok I have now had time to look at all the info in site. you guys have the actual maint manuals and it takes you step by step through all of this and they give you basic diagnosis.

i will be quit now. you wont need me yamering with this info in your back pocket:)

nice info. I put a copy in my tough book and it is also my nav computer.

today is a good day as i learned two new things today