Beginning of season engine trouble

[sneuman]

I just tried to start my Isuzu 55hp diesel for the season. It cranked, sputtered, almost started and then successive cranks sounded like the batteries were running down (they weren't). a whir whir whir ... nothing.

If it's vapor lock, it would still crank, right?

Any thoughts?

[drh1965]

I know this doesn't answer your question exactly but... If you have a decompression lever, I'd crank it with that held out until the engine turns over freely making sure it doesn't start (how ever that is done on the Isuzu). Then try to start it when it seems to be turning over smoothly. Did you change the oil? I'm sure it takes a few seconds of cranking to recoat the internal engine surfaces with oil before the engine will turn over freely if its been sitting idle for months.

[sneuman]

thanks. so you think it's a lack of compression? wouldn't it crank without firing if that were the case?

I don't think the Isuzu has a compression lever.

[stevensc]

Are sure your batteries well charged?
A whirring from the starter would probably mean the starter gear is not engaging the gear on the flywheel, just spinning free. Could be stukc on the starter shaft.
There is a website called boatdiesel.com which has lots of information on all sorts of marine engines and components you can read posts and some articles for free but to post a question you must join @ $25.00 per year. There are some very experienced folks there who you could contact privately.
Good luck
Steve

[DeepFrz]

Sounds like your starter is not engaging. Is your battery charged? I would check and clean if necessary all electrical connections leading to your starter and solenoid. You may need to remove your starter and have it serviced.

[AnchorageGuy]

The big question to start with is, are you sure about the batteries. That would be the logical starting point. You need to check the battery voltage when the starter is engaged to see what the voltage drop is. From there go to the starter and check voltage and connection. Then move on from there.

[Inthewind]

Check to see if your battery cables are getting hot while trying to start. If they are getting hot you could have a faulty cable. Check your ground cable to make sure it is grounded properly and corrosion free, sometimes adding a second ground cable helps.

[jrd22]

Hard to tell from your post what is happening. I would start by fully charging the batteries and then try the starter to see if it sounds better. It would be pretty typical after sitting for the winter to have a battery go bad. If you are sure the batteries are good, and fully charged, you might need to investigate the starter, but start with the easy stuff first.

John

[Alan Wheeler]

Hi Scott. OK two possibles here. One is that the Batteries are in fact running down. I will assume you have checked that and ruled it out. The second is that the starters bearings are getting worn. This will cause excessive load and the starter will slow down and make the same impression as a flat battery would. A Diesel, especially cold and extra especially if it has no glow plug or pre-heater, needs good cranking speed to ensure very good compression which produces the heat which produces that bang.
The other issue is that over time, the fuel may have drained in the injector system side, just enough for an air bubble to form. That is all it takes to stop the engine firing properly on initial start.
No I don't believe those engines have a Decompression lever. Most Japanese engines have what is called Interference fit engines. That means if the valves are held down, the pistons can hit the valve. That results in permanent decompression which isn't a great look for their engine.

[Alan Wheeler]

post a question you must join @ $25.00 per year.

Why would you want to part out with $25.00 when we have some of the best mechanics in the industry right here.

[Zach]

I'd bet you have a corroded connection or tired cable between the starter and the battery. If you check the voltage at the battery, vs the poles of the starter (not the cable end, but the pole) and there is a difference you found the problem.

If you have wet cells pop the caps and make sure the plates are covered too. It'll have enough power to make you think its strong, and read voltage. Apply load to them and they cry uncle. (If you have an old charger that doesn't float, this may be your problem.)

Good luck with it, always a bummer when they don't start up after resting all winter.

[johneri1]

I'd for sure check the fuel i.e., no water in filter/collector; I had one fail to start last year for just that reason.

[David M]

My guess is you just wore down your batteries doing all that cranking and the real cause is lack of fuel...because if you have fuel the engine will start without a lot of cranking.

Get the batteries charged back up and try again. This time back off one of your injector inlets on the top of one of your injectors and see if any fuel is squirting out...don't take it off all the way...just crack one of them open a little. Are you getting fuel then? Over long periods of time, diesels can lose their fuel prime and my best guess is that is what has happened.

Do the simple things first before you start taking things apart...and this is as simple as checking your diesel for fuel gets.

If you are seeing absolutely no fuel squirting out then your engine manual has the procedure for priming your particular engine.

[DeepFrz]

Hey Scot, how are you making out with your engine?

[DeepFrz]

Hey sneuman, how did you make out with this?