BMC 1.8 Charging Issue

[Flocal_1980]

Evening all, I have a intermittent issue with my alternator / engine. This has only happened a handful of times and has been playing up tonight.

Start the engine, always let it warm up for a few minutes, then increase the revs for the Alternator to kick in. The issue starts when I do this. Doesn't matter if I give the engine quite a lot of revs, the meter is telling me 13.9v and won't go above. And the engine tone sounds different in the cabin. Slight increase and decreases in revs and vibration.

Has not done this for ages, usually sits at 12.2-4 quite happily and no engine tone noises.

Ive been told the erratic revs could well be a fuel pump issue, a spring or something not sitting right at the fuel inlet.

So could be that playing up...

Cheers

[MtB]

Evening all, I have a intermittent issue with my alternator / engine. This has only happened a handful of times and has been playing up tonight.

Start the engine, always let it warm up for a few minutes, then increase the revs for the Alternator to kick in. The issue starts when I do this. Doesn't matter if I give the engine quite a lot of revs, the meter is telling me 13.9v and won't go above. And the engine tone sounds different in the cabin.

 

 

Loose vee belt I'd say.

 

 

 

Slight increase and decreases in revs and vibration.

 

 

Different issue, I'd say....

 

Has not done this for ages, usually sits at 12.2-4 quite happily and no engine tone noises.

 

 

Yet a third issue. That's far too low a voltage.

[ditchcrawler]

 

 

 

 

Yet a third issue. That's far too low a voltage.

Not if his batteries are flat and it hasn't started charging

[MtB]

Not if his batteries are flat and it hasn't started charging

 

 

As the OP says 12.2v to 12.4v is the usual charging voltage, I'd say he is progressively and rapidly goosing his battery bank.

[Boat&Bikes]

Bet he pops back on to post he meant 14.2 to 14.4...

[ditchcrawler]

Bet he pops back on to post he meant 14.2 to 14.4...

I'm not holding my breath

[Flocal_1980]

I'm not holding my breath

Hope u didn't pass out

And ure right, should of said 14.2-3...

 

And Mike, still as helpful as ever, move along.

[Tony Brooks]

What is the voltmeter showing before you start?

 

Once again for all novice and not so novice boaters: - the higher the alternator charging current the lower the charging voltage. A high charging current implies a high load on the engine and potentially a different sound.

 

Certainly check the belt and if its OK run at (say) 1500 rpm for an hour or so and see if the voltage gradually climbs, on the basis of what you have said apart from the comment about erratic revs all seems symptomatic of a well discharged battery. However take care, much depends upon what alternator you have fitted. Early alternators were set to 13.8 to 14.2 rather than the more normal 14.2 to 14.5ish these days. Photo or identification?

 

 

More about the erratic revs. If the revs go up and down and it sometimes stalls as it revs fast then I doubt its a spring. It is more likely to be an air leak into the fuel system or a blockage starving the injector pump of fuel. A few 1.5s use a mechanically governed pump and those should not exhibit these symptoms. So a better description of what you mean and possibly a photo of the injector pump.