engine stalls after five minutes

[Ernie tetrault]

Hi,I have a 1979 H33 with a Yanmar 2QM15 aboard. Last week while cruising, the engine started slowing down. It helped a little to increase throttle, but eventually it just died! I had just topped off the tank before leaving port, so I suspect tank sludge was dislodged and sucked into the intake tube.Anyway, I have since replaced the tank (it was in need anyway), and the low pressure fuel feed pump. It was not pumping with the manual lever. I have also checked all fuel lines for flow. All okay. I bled the system, and again it runs great for exactly five minutes and dies.I read the posts concerning Alan Eland and his "air in fuel line" dilemna. I didn't know about the small bleeder screws that are mentioned, so I'll try that next. But I was wondering if there's something else I should try. Would it run for five minutes if there was air in the system?Like Alan, time is precious. I start a week of vacation tomorrow and would like to be able to rely on the engine.You can also email me directly at ernie.jt@home.comThank you!Ernie

 

[Fred Moore]

5 minute woes

After just experiencing almost the same problem perhaps I can help. When motoring I lost power (rpm down to 1500 max)increasing the fuel caused lots of black smoke. The problem came and went. Because it happened during a run in heavy seas, I assumed that had kicked up some junk from the fuel tank and cloged the filters, after replacing the filters and bleading the injectors, the engine ran fine for 5 minutes, then died, when cracking the injectors there was no fuel there, It turned out that I hadn't bled the fuel filter on the engine properly. After letting the boat sit for a week, restarting the engine again I had no power same 1500 rpm trick. pulled and clean the injectors incase I got some junk in there when changing the filter resolved nothing. I had good fuel flow to the injectors. Next I pulled the injectors, and the injector pump and had them checked. Number one was putting out low pressure but was working, Number 2 was putting out lower pressure and not firing the injector at all. A 278 dollar rebuild of the injector pump not only resolved the problem, but increased the power of the engine, I now get another 200 rpm, but the response is like I replaced the engine. Guess the seals slowly deteriate untill they fail totally. Hope this helps.

 

[Bryan C.]

Have you changed your fuel filters lately?*

Sounds like a fuel flow problem.