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

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.