Trouble starting engine when hot, soon after shutting off

[jipcho]

Hi all,
I have been plagued by an annoying problem for a few months.
This problem occurs sporadically. It doesn't always happen.
After running the engine (Volvo Penta 50 hp MD 22L) for an hour or more, I shut it down, sail for a bit, and then try to start it again to enter the harbor. I turn the key, hear the click, but no cranking whatsoever. I check that all the connections to the starter, solenoid, alternator, injector pump, grounds, are tight, and try again. Sometimes it works. Sometimes, still no cranking, so I manually turn the crank shaft with a spanner to change the position of the pistons/valves. Sometimes this works, sometimes I have to do this 3 or 4 times before it works. At some point it cranks again, and starts right up. It has always started, but sometimes it takes 5 or ten minutes before starting. In an emergency, I don't want to have this worry. I am at a loss as to what may be the cause. Could the manual turning of the crank shaft be helpful, or is it just dumb luck, and there is a different problem? The problem only occurs when the engine is hot (not too hot), and recently shut down. It has never happened when starting a cold engine.
Any ideas? Anyone ever had a similar problem and found a solution?
Thanks all!
David

[a64pilot]

I don't think turning the crank has anything to do with it at all. I believe it is an electrical issue, likely with the starter solenoid. To determine if it is the solenoid, try jumping battery power directly to the small terminal of the solenoid when you have the problem, if it always starts when you go direct from the battery, then it's not the solenoid, it's likely the switch or wire supplying power to the solenoid. If bypassing the starter switch does not alleviate the problem, then it's likely the solenoid, maybe dirty contact points inside of it, but replacement is a longer lasting solution than cleaning the contacts.
This is I believe not an isolated problem, many times it's fixed by installing another solenoid close to the big starter solenoid as often the starter switch and or the wires to and from it are undersized and they don't supply enough current to operate the big starter solenoid.

But, it could be as simple as a loose ground too, so check all the easy stuff first

PS, I have the same problem with my Yanmar, mine I know is the switch / wire, I need to install a second solenoid

Oh, have someone show you how to jumper the starter with a screwdriver one day, so you will know how if you need to one day in an emergency

[MarkSF]

Yes, I had the same problem. Bought a new starter motor, end of problem. Problem is heat soak of the starter combined with a internal problem with the solenoid or brushes.

This was After replacing the battery, all the cabling, the 1-2-both switch........

Would be a good idea to eliminate other issues as the cause, as A64pilot has suggested. Suggest testing the supply and solenoid voltages to the starter when the fault is present. However, I appreciate the fault might be difficult to reproduce (mine would only do it in a shipping lane, after the wind died, with a container ship bearing down on you), so the alternative is to check all connections are tight, check condition of battery cabling, and simply throw a new starter in.

On the plus side, the new geared starter is half the weight and size of the old one, and turns the engine over faster.

[Boatyarddog]

Pull starter solenoid power from the battery connection at the starter motor, instead of the key switch.
You've got resistance in that circuit.
Like a remote starter switch, your just jumping across to the + battery terminal at the starter to the starter solenoid terminal.
You can add a relay if you want.


Sent from my iPad SV Cloud Duster

[Cheechako]

I vote electrical issue also.
*Does your control have a switch that avoids you starting while in gear? if so I've seen that switch fail and be intermittent.
*Also, check any multi wire connectors (like the back of the engine) for corrosion inside.
*Also could be a key switch issue or connections on the back of the panel...
* As mentioned above, when it's acting up try bridging at the solenoid and see if it cranks.

[MarkSF]

All worth trying, but I bet you end up changing the starter motor. By my reckoning, your starter is now at least 20 years old. That's the kind of age when they start playing up. My first car included a wooden mallet as standard equipment, for hitting the starter motor with.

Adding extra relays is essentially sticking lipstick on a pig. There's a reason you have two circuits in a starter motor. The low current circuit activates a relay that engages the starter high-current circuit. You shouldn't need a relay for the relay.

"Could the manual turning of the crank shaft be helpful, or is it just dumb luck, and there is a different problem?". Not dumb luck, it's having the same effect as the wooden mallet. Or doing a rain dance. Or just waiting. Eventually the sticking solenoid, loose connection, or sticking brushes makes contact.

[dlymn]

Same problem on my Yanmar. It has no problem starting using a screwdriver across solenoid and battery lead. I agree on poor lead to solenoid. I worked out that there are 7 separate connections between the battery and the solenoid. It would not be hard for corrosion to build up on one of them
. I will rewire direct from ignition key to solenoid to remove some of them. Will use 6mm wire about 2 meter run.

P S yes, it always and only happens when there's an emergency or I have guests on board.

[Stu Jackson]

Listen to a64 and Mark, they're right. They already noted it, but check your engine ground connection.

FYI and BTW, this is a not unusual issue. You are not the first, nor the last.

[MarkSF]

My greatest problem was that it was SO intermittent. Once every few months at the most inopportune moment.

I've now got new 00 gauge battery cables, a new group 31 battery, a new starter switch, a new 1-2-both switch, new wiring to the solenoid, and finally a new starter.

In pursuit of the fault, I found all kinds of issues. Badly done crimps, dodgy wiring, you name it. It's just that none of them were the final fix.

It doesn't half start nicely now, though!

[NoTies]

As you're hearing the solemoid click (assuming it doesn't have an auxillary solenoid fitted) then the problem is in the starter motor or a voltage drop on the heavy positive or negative leads. Your key function and light wire to solenoid will be OK.

[phstol]

Could equally be any one of: wiring; solenoid (mechanical sticking of the internal plunger caused by corrosion); starter motor (caused by a bad winding going intermittent, and the motor will not turn if the brushes came to rest on that winding last time it stopped).
The latter 2 can be temperature dependent b/c of dimensional changes.
I wd start by checking first whichever is easiest for you depending on your skill/situation.
I wd definitely eventually replace all 20 yr old wiring, but this might not be the cause. If it is accessible you can unship the starter motor/solenoid and take them to an automotive shop for testing.
Some one mentioned a wooden mallet. A quick test for the sticking solenoid is to give it a couple of sharp whacks with a small steel hammer while someone turns the key. A wooden mallet doesn't deliver the right kind sharp mechanical pulse.
good luck!
Peter

[MarkSF]

"If it is accessible you can unship the starter motor/solenoid and take them to an automotive shop for testing."

Unfortunately, that's not going to tell you much, if you have a problem that's very intermittent, and only happens after heat soak.

A new Denso starter for mine was $80. Not worth messing about at that price. Plus removal is a nightmare. Having removed it, there's no way I'd put a used one back in.

[clyde]

whenever one hears a 'click' when trying to start an engine, 99 times out of 100, it`s a loose connection! on cars it`s usually a loose connection on the battery terminal...a bad crimp, etc...as the others said, play the elimination game!...clyde

[phstol]

MarkSF,
yup, at $80.00 I would replace it without another thought. Way better than the container ship someone mentioned above.
I wd still redo the 20 yo wiring.
Peter

[Derek Lumb]

Before you spend any money clean the battery connections. You sometimes get an oxide which is heat sensitive which can cause this type of problem. Once you have eliminated that then work through the electrical system - it is very lilekely a "high" resistance joint somewhere but note - it only takes 0.1 ohm in the starter circuit to disrupt it - a starter motor draws 150 - 200 amps so 0.1 ohms will collapse the voltage. It will also get hot making matters worse - most materials have a positive heat coefficient ie the hotter they are, the higher the resistance.

Start with the solenoid - measure the voltage across the contacts. It should start at around 12v but when the starter is operated it should drop to <1 volt. If its reading significantly more than this then it is most likely the contacts so it need changing. If the voltage doesn't change at all then it is likely to be on the control (low current) side so that needs checking out. If that is all OK then carry on through the starter circuit checking in the same way. Any hot connections are a dead giveaway. If the voltage across the starter is healthy (say >10v) then that points to the starter itself which is most likely brushes.

Good luck.