Trouble starting engine

[ghebbns]

Just at anchor now after a great day off sailing. We stopped at an island to explore the beach on our way here. Afterwards, the wind was in our face so we motored for a bit. The wind was quite strong so the engine had to work pretty hard. After the wind shifted, we pulled out the sail for a bit but it shifted again and we needed to start the engine. No joy. It turned over but obviously was not getting enough juice to start.

I turned off all electronics and it did start. I had a similar problem last year and it turned out to be bad ground connections on my batteries. I cleaned them up and all was good. Once we anchored today, I checked then again. They looked good but I gave them a cleaning anyway. I tried to start on one battery but no good. I then cleaned the ground connection on the engine and the motor turned over with one battery.

Both batteries are fully charged. I believe I read somewhere that hot engines take more current to start than cold engines so I am not sure if I fixed the problem or the engine had just cooled down. Not sure if it is related, but there appeared to be some black soot on the alternator.

After all that, my question is what else could be causing the problem. If all connections are clean and the batteries are charged, what else could cause slow starting?

Thanks

[KWKloeber]

 First, how do you know your batteries are quoting fully charged."? How are you determining their SOC??

Secondly give us more information.  What engine?  But your boat/engine information in your  profile so it's always there. Makes it a lot easier.
What are your battery capacity? What upgrades have you done to the electrical? What size are your battery cables? Etc. etc.

[Ron Hill]

gheb : FYI, a hot engine doesn't need glow plugs!!

Beside the questions that Ken asked, tell us about the "won't start":
It won't crank?  It cranks slowly?  It turns over rapidly?  You can hear the electric fuel pump?  etc. etc.

A few thoughts

[ghebbns]

Sorry for lack of information. Pain in the ### typing on your phone.

It is a 25 xp. No electrical upgrades other than replacing the engine gummy connectors.
One battery tests at 12.85 volts and the other at 13.05. They are diehard Platinum Marine.

Not sure of gauge of wires - probably original for a 1990.

The fuel pump clicks no problem. The engine turns over but too but slow to start. Like a car in really cold weather.

[Jim Hardesty]

Try checking the connections on the starter and all other big-wire connections.  ie. engine ground 1/2/both switch
Wish you luck getting started.
Jim

[KWKloeber]

First read all the 101 electrical

if ALL terminals (both pos AND neg) are ok as you say, then there are three prime possibilities. (1) Battery capacity, (2) excessive V loss in the cables, and (3) the starter. 

You can troubleshoot 2 and 3, but the simplest to eliminate may be to have the batteries stress tested.  How old are they?  Are you tied to a shore charger every night, or on a mooring?  First test them with a hygrometer.  Take them to have tested by someone who knows what they're doing to properly measure their remaining CCA on a good tester, not just a quickie hand held.  I have had batteries that tested fine at rest, but didn't have enough ooomph to a turn over in their own grave.  I have also had batteries with one bad cell, that tested fine on the thousand $$ super-duper tester.

The battery cable gauge should be embossed into or printed on the insulation.  If it's OEM 4 awg, upsize them.

You can troubleshoot by measuring V loss at several points while cranking, but unless you KNOW that the batteries are good, I would start there.

If V to the starter is ok, then the solenoid contacts may be corroded and not passing full V to the starter motor.  Again that's troubleshooting with V meter while cranking.  Or the starter motor itself may be weak.

I presume that since she turns over, that the V supplied to the solenoid is sufficient, but also something else to check.

kk

[ghebbns]

Follow up:
Started the engine this morning and it turned over with no hesitation.  There was no wind so we end up motoring home for 2.5 hours.  After we tied to the dock, I tried to start it while it was still hot and it went no problem.  Waited 10 minutes and tried again, and no problem.  So it is possible that it was a bad ground connection on the engine

HOWEVER

while on the hook last night I was doing some inspection.  The trailer connector has been replaced on the engine end of the harness but the engine panel end still has the gummy connector.  Obviously this is my first priority to change over the weekend.  I know it is hard to tell without more information, but is it possible (or even likely) that this may have caused my problem?  I am trying to convince the Admiral that she will not have to worry about the engine starting once I fix this :)

Thanks for all the advice.

[britinusa]

Do you have an Ampmeter in the Engine Control Panel or a Voltmeter ?

Paul

[KWKloeber]

Based on what you report, not likely that panel gummy is affecting the  starting. 

You said it turned over, but slow.  The only function the gummy and harness has on starting, is to energize the starter solenoid.  So, if that was energizing okay, then the harness and gummy **should** be ok.   

I suppose a **borderline** voltage delivered to the solenoid might cause a weak connection at the terminals when the switch closes, but that's a real long shot. it would be more likely that you **start** and get no action from the starter or a click at the solenoid.  But with what you explained, I would suspect batteries (AGE??) and cables.   

As Paul implies, if you have an ammeter, then it affects your charging (but not the starting directly.)  But you **said** they are fully charged.  BTW, I would never necessarily rely on the panel V meter as a final word on the battery SOC.  the Vs you mentioned may or may not be good, depending on your batteries, age, etc.

Note that I have seen at least two panels wired **wrong,**  -- one with the preheat on with the start button (robs voltage to the starter solenoid).  Another with the preheat on when the key is on (robs voltage and burns out the plugs.)  Check for that.

k

[KWKloeber]

Additionally, if your battery neg cable is on a bell housing bolt, move it to directly on a starter bolt.

k

[Ron Hill]

gheb : With your statement of battery voltage in the 2nd decimal, I assume that you are checking Voltage at the battery/s with a multi-meter? 
If your contacts are clean as you say and you haven't given the battery/s age, I'll guess that you need to take the battery/s and have someone run a draw down test.  Advanced Auto or Batteries + will give you a free Check.

If you are able to turn the engine over and a diesel doesn't start - you'd better look at fuel!!

Don't forget to give your hull# & production year

A few thoughts

[Stu Jackson]

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1.  Not sure of gauge of wires - probably original for a 1990.

2.  The fuel pump clicks no problem. The engine turns over but too but slow to start. Like a car in really cold weather.

1.  Would be #4.  I had a loong discussion with Maine Sail over on sbo.com a few years ago.  He has been recommending MUCH larger wire.  Based on voltage drop he's quite right.  I did get him to agree with me that my OEM #4 wiring has been working lo these 30 years on my boat.     If I was re-wiring I'd go bigger, but I'm not and won't be doing so.  If you are, you should.

2.  Advance your throttle.  As long as the starter works, engage the glow plugs longer on a cold engine, and/or install the glow plug solenoid (see the tech wiki).  A hot engine doesn't need the glow plugs. 

>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>I believe I read somewhere that hot engines take more current to start than cold engines so I am not sure if I fixed the problem or the engine had just cooled down. Not sure if it is related, but there appeared to be some black soot on the alternator.>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>
Thanks

Nope.  The issue is that with BAD connections on the wiring, those bad connections heat up because they're unable to carry the current flow properly.  Hot engines do NOT take more current.  Hot wiring with crappy connections interrupt the flow of power.  That's why.

Black soot on the alternator is belt dust.  Align the pulley properly.  Discussed in both Critical Upgrades and Electrical Systems 101.

[ghebbns]

Thanks again for all the help.  I will have to check the batteries age but they came with the boat and that was 5 years ago.  Wouldn't be a bad idea to replace them as I am probably on borrowed time with them anyway.

[mark_53]

If you still have the OEM starting circuit using #4 wire, you will never have confidence in starting because the wire runs are too long and connections to many. Put in a dedicated starting battery as described in Critical Updates.

[Springfield]

Thanks again for all the help.  I will have to check the batteries age but they came with the boat and that was 5 years ago.  Wouldn't be a bad idea to replace them as I am probably on borrowed time with them anyway.

Right, lead-acid batteries of the electrical starting system may last many years, but they are certainly not immortal. Also, you can configure a spring starter as Plan B to start the engine in an emergency when the battery cannot work normally. I find this article, hope it would help. https://www.cqstart.com/articles/detail/cqstart-spring-starter-mechanical-emergency-engine-starter.html