Starting woes (help!)

[Lochnevis]

Well, the new heater plugs turned up yesterday.  I fitted them this morning, and it started! The starting isn't quite as good as it was when I got the boat (when it didn't need any time on the heater plugs, and fired straight away), but it only needed a couple of seconds (after ~15 seconds of the heater plugs).  So, problem solved, thanks again all!  I'll take Tony's advice and leave the rocker cover where it is, though I am tempted by the the idea of getting a compression tester, as suggested by Scholar Gypsy (mostly because I love a good gadget...). 

A very quick check of the battery voltage suggests that the alternator and/or wiring are in trouble, though (13V at the battery terminals, after giving the battery a good charge on solar charger), but further investigation of that will have to wait until the weekend.

[Boater Sam]

I find that more than 7 or 8 seconds on the heater makes little difference to the starting other than it pulls the battery down and reduces cranking speed slightly, especially if the battery is getting a bit tired or not fully charged.

[doratheexplorer]

12 hours ago, Boater Sam said:

I find that more than 7 or 8 seconds on the heater makes little difference to the starting other than it pulls the battery down and reduces cranking speed slightly, especially if the battery is getting a bit tired or not fully charged.

I find the opposite.  A good 10-15 seconds heating the plugs and the engine fires almost instantly.  If I try to crank from cold, it takes ages to start.

[WotEver]

11 minutes ago, doratheexplorer said:

I find the opposite.  A good 10-15 seconds heating the plugs and the engine fires almost instantly.  If I try to crank from cold, it takes ages to start.

The Vetus on WotEver required 20+ secs on a cold day

[Lochnevis]

Moving the boat today, it does seem to struggle to turn over, but then goes after a few seconds (<5 seconds).  This applies even when warm - as the engine needs to be turned off in Thames locks,  I had a chance to test a few times!

The starting is now what I would consider absolutely fine, but as it didn't used to do this, I'm now a little worried that there's an underlying problem which I shouldn't ignore (or that I've knackered the starter motor a bit with the repeated long cranking attempts!).  Does anyone have any words of wisdom?

[MtB]

22 minutes ago, Lochnevis said:

Moving the boat today, it does seem to struggle to turn over, but then goes after a few seconds (<5 seconds).  This applies even when warm - as the engine needs to be turned off in Thames locks,  I had a chance to test a few times!

The starting is now what I would consider absolutely fine, but as it didn't used to do this, I'm now a little worried that there's an underlying problem which I shouldn't ignore (or that I've knackered the starter motor a bit with the repeated long cranking attempts!).  Does anyone have any words of wisdom?

 

Have you removed that fuse from the starter circuit and resolved the problem identified in post 10? 

 

 

 

 

 

 

[Lochnevis]

2 hours ago, Mike the Boilerman said:

 

Have you removed that fuse from the starter circuit and resolved the problem identified in post 10? 

 

 

 

 

 

 

The fuse has been removed.  Troubleshooting the alternator is going to have to wait for the weekend, but the new battery was given a good charge from the solar.  Though if the alternator is broken in a way that is actually discharging the battery (is that possible?), I guess the battery voltage might now be low (it's had ~4 hours running since I changed the heater plugs).  I'll check the resting voltage when I'm back on the boat.

[Tony Brooks]

3 minutes ago, Lochnevis said:

The fuse has been removed.  Troubleshooting the alternator is going to have to wait for the weekend, but the new battery was given a good charge from the solar.  Though if the alternator is broken in a way that is actually discharging the battery (is that possible?), I guess the battery voltage might now be low (it's had ~4 hours running since I changed the heater plugs).  I'll check the resting voltage when I'm back on the boat.

It is possibly but if that were the case the alternator would be hot and that and the wiring would probably be smoking or burning. If there is a fault it is more likely to be one charging coil; inoperative for some reason but rested voltage is not a very good indicator for that because even if one coil was not working you could still get 13.8V and given time that would   fully charge the battery. You need charging current at the start of the day or with a well discharged battery and charging voltage at the end of the day & compare with the data for that alternator.