27 replies to this topic

[hellom8]

Hi,

My 91 1275 auto has an issue starting/turning over the engine.

The battery has to be charged to 14.7 volts and start on the first attempt.

Any attempt to start the car after that, then the engine bearly turns a rotation and then stops turning.

Even trying to start the car with a booster dosen't work, it has to have a fully charged battery.

The battery is new, HB075 with 500 CCA.

Is this likely to be a starter motor issue?.  I have a multi meter but don't know what tests to do to issolate the issue.

Any ideas?.

Cheers.

Iggy

[firstmini]

I am def not a mechanic so could be completely wrong, but thought I'd reply as it sounds exactly the same as my issue a few weeks back - was having to put a booster pack on & plug it into the mains for over an hour for the battery to charge up enough for me to start it. The mechanic I use had the car running and tested the battery which came back at under 12v so diagnosed it as needing a new alternator. Has started first turn of the key everytime since.... As Ben's signature says (Im Sure it's Ben O) an expert will be along shortly.

 

Hope you get it sorted

[hellom8]

Thanks for the idea.  I will stick a multi meter on the battery when the car is running and see what voltage is coming back.

Edited by hellom8, 16 December 2014 - 01:49 PM.

[firstmini]

No prob, worth a try

[Jedi Master]

Sounds the same as my issue. Has been getting slower and slower on turnover for quick some time. Finally the battery died this morning after only x3 attempts. Alternator is still the original since 1978. Battery is new, but
I doubt getting much charge when running as I have the lights, wipers, etc all running. Battery has likely been getting slowly run flat by this process. I'm guessing the older alternative kicks out relatively lows amps compared to a modern type so not charging the battery very well, if at all. My '93 auto spins over very freely in comparison.

[Spider]

Could well be the alternator and that would probably be one of the first places I'd look.

 

I did have one a little while back where it was the starter motor. On the Bench it seemed OK, but the bushes (not brushes) were worn and so it was 'poleing out' where the armature starts to rub against the field poles.

[hellom8]

Thanks.

I will check the voltage coming back to the battery and also check to earthing to make sure that's ok.

Does anyone know what sort of voltage should come back from the alt?.

Cheers.

Iggy.

[Spider]

At least 13.5V but closer to 14V would be more pleasing.

 

Also check at the battery too.

[hellom8]

I'm getting 13.9V at the battery.

I did notice that the battery earth was quite loose, so I have nipped it up.

Edited by hellom8, 23 December 2014 - 01:59 PM.

[KernowCooper]

The Voltage on the regulator was listed originally at 13.7-14.3v at 2000rpm+ for reference and the lower figure being the minimum to charge a Lead Acid 12v Battery

[dklawson]

You mentioned checking the battery earth.  My thought was that if you can slowly charge the battery and it seems to run out of power after one or two attempts to start the engine, it may not be the battery itself but the earth cable(s) both in the booth and in the engine bay.  If the conductors or their attachment points are corroded or eaten away by acid the reduced conductivity can result in heating while cranking that further reduces the ability to pass current.  While checking all the inexpensive things, check the cables and their anchor points, cleaning and replacing as necessary.

[hellom8]

Thanks.  I will remove the earth straps and clean with IPA to see if that does the trick.

[dklawson]

The alcohol is not what I had in mind.  Use an abrasive like wet/dry paper or ScotchBrite to clean all the cable contact points (both on the cable terminals and the car body) to shiny bare metal.  Coat the cleaned surfaces with Vaseline or dielectric grease and reassemble.  While working with the cables, try to examine them closely for corrosion damage that has crept up under any cable insulation.  Cables can look intact and have hidden damage under their jackets.

[hellom8]

Ok, thanks for the advise.

[gazza01]

If everyone cleaned up thier earthing points many of these electrical issues we read of would be sorted.