Starting an engine after a year ashore - low cranking speed

[kacecar]

My boat has just been re-launched after a year on-shore "fixing" various things and the time has come to start, or rather re-start, the engine. The engine, a raw-water cooled VP2003 (yes it's old, but it has always been well looked after), was working perfectly before it was taken out and, beyond some protective measures and normal maintenance items, did not require or receive great attention while out of the boat. Subsequent re-installation proved straightforward. As far as I know, all connections have been re-made successfully, without incident / issue (by me, rather than by a professional).

Now, back in the water, it is time to start it but the cranking speed is low and the engine is refusing to start, even to cough, or splutter. Up until taking it out of the water last year, and since I've had the boat (16 years), the engine has started reliably and after very few revolutions - but not now.

The batteries (3) aren't new (two years old) but have themselves been maintained over the last year and appear capable of taking a full charge. Putting an extra battery (a big jump start pack) into the circuit (at the batterypoint rather than direct to the starter - direct connection requires a separate cable) has no apparent effect. I've dismantled, cleaned and re-assembled all the connections, from battery to block, that were disturbed during the engine removal and installation process. There appears to be plenty of fuel at the injectors.

I suspected starter-motor but cranking while the engine is "de-compressed" produces the anticipated increase in revs (although, it might still be turning slower than should be expected - I'm not sure) and I wouldn't expect starter-motor performance to degrade just by standing for a year in a proteced environment.

I'm planning to make up a cable so I can attach a battery directly to the starter motor and try that, but I can't do that today so, in the meantime, I thought I'd ask the forum. Any ideas as to what might wrong and/or what to look at next? All suggestions / thoughts will be gratefully received.

 

[lw395]

I would measure the volts at battery and starter motor while cranking.
If possible, measure the current too, if you have access to a DC clamp ammeter.

One thing at a time. You need a reasonable cranking speed.
Without that, the engine has lots of excuses not to fire. A bit of air in the fuel, slightly low compression, whatever.

 

[JumbleDuck]

Does the engine have decompressors and, if so, what effect does opening them have?

Are you absolutely sure that it's out of gear?

With the belt off, does the alternator spin freely? I had problems with my 1GM10 starting from hot which turned out to be an alternator which was getting tight when warm.

If you have a starting handle, how easy is it to turn the engine with that?

 

[macd]

Does the engine have decompressors and, if so, what effect does opening them have?

The OP's already answered that, JD.
The first suspect with this must always be power to the starter, so jury-rigged leads on both pos and neg is a good test.
Failing that, the suggestion of removing the alternator belt is a good one, although obviously if it does then start, it should be run for only a few seconds.

 

[RichardS]

Does the de-compressor operate on all 3 cylinders?

The only time I had the same problem with slow cranking with a diesel car engine, I connected two fully charged batteries in parallel and it did not make any noticeable difference and the engine was still too slow to start. It turned out that the head gasket had failed and hydrolocked a couple of cylinders.

Your engine is raw water cooled so that seems a remote possibility plus if the decompressor operates on all cylinders any fluid (oil/water) causing a problem should be ejected.

If you get the engine spinning more quickly with the decompressor lifted and then drop it suddenly does that generate a firing stroke?

Richard

 

[Deleted member 36384]

Okay, so this is large traction motors that power drilling rig equipment, but they are very similar to your starter motor. If I lay up a rig and cold start it, what we find is that the carbon spreads across the commutator and the DC motor does not perform with the required power.

Scaling this down, your starter motor's commutator may have a build up of dirt from the carbon brushes and moisture over the layup has allowed the dry carbon to smear. Inspect the commutator and clean up with meths and cotton buds if it looks like shit. You may have to do more than just clean up because the carbon shorts across the gaps in the commutator and sometimes you need to clean it out - that is big job. On my rigs we have large inspection hatches for this type of work, not the case on the starter motor.

 

[neil_s]

I note that you took the engine out, presumably you disconnected the fuel lines. Is the engine getting some fuel now you've re-installed it?
Another thing you could try is blowing warm air into the air intake as you crank.
VP's have a cold start mechanism - is it set for starting?

 

[wully1]

I heard a story yesterday about someone experiencing a similar problem - turned out to the a blocked exhaust elbow...the back pressure was too much for the starter!

 

[kacecar]

Thanks for all the ideas so far. Looks like I'll need an assistant!

LW395 - I'll try to check the voltages as suggested.
Jumble Duck - It's not supposed to be in gear but, as I've had all the controls off, checking that is a good idea. I'll take the alternator belt off too.
MacD - I've already tried an extra battery to no avail but only using jump leads and not connected directly to the starter. For that I think you are right about needing extra cables properly fixed at the appropriate points to get a good connection. I'll look for some suitable cabling.
RichardS - I suppose the headgasket issue is a possibility . . . . but I certainly hope that isn't the problem! Not sure how I check that so, at the moment, investigating that one goes some way down the list. There's absolutely no firing going on.
BlowingOldBoots - That's interesting about the commutator. I'll have a look (when I've worked out how to get the thing off with the engine in situ).
Neil_S - It seems to be getting fuel OK but I'll crack the injectors again to check. The VP cold start routine is being followed as appropriate.
Wully - That's interesting, but I had the elbow off and cleaned it while the engine was out (as it happens, it it was virtually clear).

Let's see what tomorrow brings.

 

[GrahamM376]

It seems to be getting fuel OK but I'll crack the injectors again to check. The VP cold start routine is being followed as appropriate.

Are you sure it's diesel at the injectors and not water in the fuel? I know many frown on its use but I would be tempted to give it a squirt of Easy Start just to see if it fires OK and maybe then keeps running.

 

[lenten]

hot air down air intake---hair dryer/hot air gun---on my very old diesel engine used to take off the air filter and burn a newspaper in front of intake---if was really cold would heat the sump up with a quick flash over with a blow lamp ----after a couple of tries you could feel the engine warm up and loosen up and more importantly start

 

[ffiill]

Okay, so this is large traction motors that power drilling rig equipment, but they are very similar to your starter motor. If I lay up a rig and cold start it, what we find is that the carbon spreads across the commutator and the DC motor does not perform with the required power.

Scaling this down, your starter motor's commutator may have a build up of dirt from the carbon brushes and moisture over the layup has allowed the dry carbon to smear. Inspect the commutator and clean up with meths and cotton buds if it looks like shit. You may have to do more than just clean up because the carbon shorts across the gaps in the commutator and sometimes you need to clean it out - that is big job. On my rigs we have large inspection hatches for this type of work, not the case on the starter motor.

Second that
Take out the motor,dismantle,clean commutator,including gaps between segments and brushes.
This worked wonders on mine as well as on the motor running my pressurised water system.

 

[VicMallows]

From the symptoms, I also think the starter motor is the most likely culprit. Voltage measurements can erroneously lead one to suspect that it must be a battery/cabling fault; however because the starter is turning so slowly, the current draw is massive ...leading to the low voltages seen.

The starter on my BUKH 20 failed in just this manner last year. The starter on my car has recently developed identical 'slow starter syndrome' .... new brush-plate ready to install as soon as we get a warm/dry day!

 

[Baddox]

The first thing I'd check is the cable and connections from battery to starter, not least beacuse it is easy and has a high chance of identifying the culprit.
It would be easy and instructive to measure the voltage drop between the battery and starter motor when the engine is cranking. Just place a meter lead on the battery +ve terminal and the other probe on the +ve at the starter. There shouldn’t be much of a voltage showing unless there is resistance in the cables or connections.
Try the same again with battery -ve terminal to bare metal near the starter or the starter -ve post if it has one.
Neither reading should show more than half to one volt difference from battery to starter.

 

[scottie]

Just a thought at least one of the older Volvos to decompress you can choose some or all cylinders by the way you turn the lever?

 

[lw395]

From the symptoms, I also think the starter motor is the most likely culprit. Voltage measurements can erroneously lead one to suspect that it must be a battery/cabling fault; however because the starter is turning so slowly, the current draw is massive ...leading to the low voltages seen.

The starter on my BUKH 20 failed in just this manner last year. The starter on my car has recently developed identical 'slow starter syndrome' .... new brush-plate ready to install as soon as we get a warm/dry day!

If lots of current is flowing, and the motor is only turning slowly, then some part of the motor is generating a lot of heat.
That's why I'd measure the current, or check what current the battery will give with a heavy load.
I sometimes use my inverter and a 500W halogen floodlight, that takes about 50 Amps, which is enough to show most faults.

It's possible to ruin a starter motor by letting it draw lots of current. So keep tests nice and short.

It could equally be the brushes sticking in their holders, this will mean it draws little current. And the volts stay high.
My shower drain pump used to do this, I found out in the end the brush springs were rusting away and losing their force!
Sorted that one with a couple of biro springs.

 

[kacecar]

Thanks everyone for all the ideas and suggestions. Here's an update. The problem isn't yet sorted, but . . . . .

All of the cable connections have been cleaned and my simple multimeter doesn't show me a significant voltage drop.
A borrowed load tester on the original start battery showed up a fault. It wasn't my tester and came without documentation so I wasn't sure quite what it was telling me but, clearly, that battery is at best suspect and at worst dead.
By using a borrowed high-tech, high power starting battery connected directly on to the starter motor (but only with big crocodile clips) cranking speed was increased - but not by as much as I would have liked and not enough to be "normal". Nevertheless, after a period of increasingly desperate cranking at the improved speed the engine did start - and strongly, not just a cough / splutter. (Hurrah!) However, I was attempting to start it on nearly full throttle so when it fired up I immediately knocked the throttle back, my aim being to restrict revs while the fresh oil was still working its way around the engine. Unfortunately I went too far towards "idle" and the thing stopped. (Bu**er!) Of course, by then the cranking required to get it to fire that first time had flattened the battery so it wouldn't go again. Never mind, at least it fired and, from the sound of it during those two or three seconds that it ran, it was firing on all three.

I've had to leave the boat now, probably for a week or so but, based upon what's happened so far and on forum advice, when I return I'll be working on the assumption that the problem is electrical rather than fuel. I'll be pursuing two potential solutions in parallel: 1) I'll assume the original start battery is cream-crackered (despite appearing OK in simple measurements) and replace it; 2) I'll take the starter motor off and clean its innards (I couldn't take it off before as it requires an adapted 10mm allen key, which I didn't then have - I do now). Perhaps I'll also obtain an assistant so I can do more measurements and play around with the decompression lever while cranking.

Thanks again for the comments / suggestions. I'll let you know how I get on.

 

[GrahamM376]

Thanks again for the comments / suggestions. I'll let you know how I get on.

Glad you've made progress and thanks for the feedback - too many don't bother.

 

[kacecar]

Several weeks have gone by since the last update (I've been busy and haven’t been able to spend much time on the boat) but now, at last, the problem is solved. The nature of the fault was a surprise to me so I’m passing it on in case others experience similar symptoms/problems.

A quick recap. I was trying to start an engine after a year unused while the boat was ashore. Preparation for starting was all normal - fresh oil, fresh filters, fresh impellor, fuel filters seemingly clear, fuel system bled successfully, etc. However, the engine would only crank slowly - and wouldn't start.

I (and the forum) suspected an electrical problem. I remade all contacts, replaced the batteries, and cleaned the starter motor innards. It still cranked slowly. I then connected a third battery directly to the starter motor. I found that with the third battery, but without doing anything else significantly different, the engine would sometimes start but would still only run for three or four seconds. A repeated attempt after such a start would feature the slow cranking again and suffering batteries.

With the electrics seemingly OK I now suspected fuel, so I stripped the fuel system from the tank to the engine filter and cleaned everything. Nothing of significance was found but I changed all the fuel filters again anyway. Once everything was reconnected and the fuel system apparently bled, I tried starting it again - no change.

At this point, frustrated at my lack of progress and fed up with the 180 mile round trip each time I wanted to try something, I called in the local engineer. Apparently he tried everything I had tried and got the same result – no change. As a long shot he swapped my lift pump (the modern VP lift pump – a sealed unit made by Sofabex) for another one. The engine cranked quicker and soon fired. After a bit of hunting and quite a bit of smoke (it is an old VP2003 after all) the engine ran well and smoothly. He had it running for over 15 mins without any other issue arising. He then stopped it, took his lift pump off and put mine back on . . . . the engine wouldn’t start again! Consequently, I ordered and fitted a new lift pump and - hey presto - everything is back to normal. The engine now cranks and starts just as easily and runs just as well as it did before.

I have no idea at all why the pump should have failed while "in storage". Perhaps some dirt got in there, although I’m not sure when / how as the only open port had been covered. Naturally, I told other sailors around the marina what we’d found – that a lift pump that had been working fine when the engine last ran a year ago had failed while unused. As is so often the way, they expressed no surprise at all: “Oh yes – they do that. I had it happen to me. It happened on Trevor’s boat too, didn’t it Trevor. And on Neil’s. Happens all the time.” Now they tell me!

And why the slow cranking? Despite the engine being well looked after, kept dry and protected while out of the boat it seems that it stiffened up for some reason. I don’t think corrosion / water ingress was an issue but suppose I can’t be absolutely sure. Perhaps the stiffness was due to a lack of oil (it was all drained out before the engine was removed from the boat). Perhaps the presence of raw diesel in the cylinder is necessary/useful as a lubricant. Perhaps a bit of diesel fuel trying to fire is just enough to help the starter motor. I really have no idea – but a bit of running seems to have cured the problem so I’m not going to worry about it any more.

Once again – thanks for the thoughts, comments and suggestions when I first posed the question. We got there in the end.

 

[RichardS]

And why the slow cranking? Despite the engine being well looked after, kept dry and protected while out of the boat it seems that it stiffened up for some reason. I don’t think corrosion / water ingress was an issue but suppose I can’t be absolutely sure. Perhaps the stiffness was due to a lack of oil (it was all drained out before the engine was removed from the boat). Perhaps the presence of raw diesel in the cylinder is necessary/useful as a lubricant. Perhaps a bit of diesel fuel trying to fire is just enough to help the starter motor. I really have no idea – but a bit of running seems to have cured the problem so I’m not going to worry about it any more.

An interesting theory and not something I have ever observed so strongly with petrol engines but I can well understand that diesel engines will behave differently and that to run freely the bore does need some diesel lubrication until the engine starts and splash lubrication from the sump can take effect. The only thing which suggests another issue is that you observed plenty of fuel at the injectors so I would have expected sufficient bore lubrication but, as you say, if it works, it works.

Richard