BrianSmith
Senior Member
- Joined
- Mar 20, 2014
- Messages
- 487
- Location
- USA
- Vessel Name
- Smartini
- Vessel Make
- 2002 Kristen 52' Flybridge Trawler
My reliable-as-can-be-for-three-years Isuzu diesel is dead in the water. After being away from the boat for a month, we returned a few days ago, and as part of our return-to-the-boat checklist, we started the engine and let it run for a few minutes, then shut it down. As always it started in less than 1 second, and ran smooth.
Today, we were going to leave the marina. Normal pre-departure checklist, instant start-up, smooth running, for about 4-5 minutes (just long enough to get a few hundred yards away from the dock, of course). Then it stumbled for several seconds and died. We were still in the harbour, so were still running pretty slowly - 800 - 900 rpm (vs. normal crusing of 1300). Made one attempt at a restart, which didn't work, so fired up the genset and engaged the get-home prop to get back to the dock. Let everything cool down for an hour or so, then started it - it started, but really rough, and didn't respond to advancing the throttle (still really rough), then it died. I tried one more time, and this time, after about 5 seconds of cranking, it didn't start, so I quit. (I have a water lift muffler, so I need to disengage the belt on the raw water pump before continuing to attempt to start it.)
I know it's not a clogged air filter, as I completely removed the filter prior to the first attempt at a restart.
I know it's not a dirty primary fuel filter (Racor 1000, 10 microns), nor a clogged fuel line to that filter, as the vacuum gauge on that filter didn't move a bit.
I'm almost sure it's not a dirty on-engine fuel filter, as I replaced that only about 3 operating hours ago, in October, just before we left for a month.
How should I proceed with troubleshoot? I'm thinking:
Step 1: replace the brand new on-engine fuel filter with another new one, on the off chance that the one I just put on is bad. If that doesn't end up being the case, then I'll keep it to be used the next time I replace this filter.
Step 2: disconnect the line from the lift pump to the injector pump and crank the engine, and see if I have good fuel flow coming from the lift pump. (How will I know if I have "good fuel flow"?)
Step 3. reconnect that fuel line, then disconnect one of the lines going to a cylinder, and crank the engine, to see if I have a good squirt of fuel every other rotation. (How much is enough?)
Does this make sense? Is there something else I should try, or should I do things in a different order?
Thanks for any input!
Today, we were going to leave the marina. Normal pre-departure checklist, instant start-up, smooth running, for about 4-5 minutes (just long enough to get a few hundred yards away from the dock, of course). Then it stumbled for several seconds and died. We were still in the harbour, so were still running pretty slowly - 800 - 900 rpm (vs. normal crusing of 1300). Made one attempt at a restart, which didn't work, so fired up the genset and engaged the get-home prop to get back to the dock. Let everything cool down for an hour or so, then started it - it started, but really rough, and didn't respond to advancing the throttle (still really rough), then it died. I tried one more time, and this time, after about 5 seconds of cranking, it didn't start, so I quit. (I have a water lift muffler, so I need to disengage the belt on the raw water pump before continuing to attempt to start it.)
I know it's not a clogged air filter, as I completely removed the filter prior to the first attempt at a restart.
I know it's not a dirty primary fuel filter (Racor 1000, 10 microns), nor a clogged fuel line to that filter, as the vacuum gauge on that filter didn't move a bit.
I'm almost sure it's not a dirty on-engine fuel filter, as I replaced that only about 3 operating hours ago, in October, just before we left for a month.
How should I proceed with troubleshoot? I'm thinking:
Step 1: replace the brand new on-engine fuel filter with another new one, on the off chance that the one I just put on is bad. If that doesn't end up being the case, then I'll keep it to be used the next time I replace this filter.
Step 2: disconnect the line from the lift pump to the injector pump and crank the engine, and see if I have good fuel flow coming from the lift pump. (How will I know if I have "good fuel flow"?)
Step 3. reconnect that fuel line, then disconnect one of the lines going to a cylinder, and crank the engine, to see if I have a good squirt of fuel every other rotation. (How much is enough?)
Does this make sense? Is there something else I should try, or should I do things in a different order?
Thanks for any input!