Very slow cranking when engine is hot

[AndrewCologne]

Hi,

it seems my starter got a problem. First I thought it could be the battery and I bought a new 77ah one. But problem still occurs.

If the engine is cold and I hit the starter button the starter in my 1950 split bug does its job/cranking normal, not as fast as in case of my 1955 oval bug, but fast enough for firing up the engine.

Now after driving the car 30 about mins and when the engine now is warm and switching off the engine and then trying to restart, the starter now cranks terribly slowly, almost not being able to turn the engine over.

All wiring harness of the car is new and voltgage is ok: about 6.35 Volts at battery with no engine running, if engine is running then the battery gets charged with about 6.8 to 7.2 volt when all lights are off.

My assumption is a weak starter and when its hot, cause of maybe worn out starter coals, it won't have enough power to crank the engine fast enough.
Or could it really be the starters bushing making the cranking that slow when engine is hot? If yes, why?

I thought asking here first before simply buing a new starter.

Thanks a lot for your assistance in advance.
Andrew
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1950 Split Window Grey
1955 Oval Window Stratosilber
1982 Porsche 911 3.0 SC Black

[vwhelmot]

I had exactly the same problem on my 56 and a new starter bush in the gearbox coupled with a rebuilt starter motor cured it. I run a yellow top optima 6v too.

[Komissar]

Too much advance timing can also do that...
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1965 Sunroof Beetle
1972 Type 3 Squareback
1978 Skoda 105S

[slow36hp]

timing or starter bushing
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1958 custom camper
http://www.thesamba.com/vw/forum/viewtopic.php?t=483656
1957 oval
http://www.thesamba.com/vw/forum/viewtopic.php?t=426468&postdays=0&postorder=asc&start=0
1957 dd kombi
http://www.thesamba.com/vw/forum/viewtopic.php?t=186478&highlight=

[AndrewCologne]

[vwhelmot]

Excellent news :D

[blood]

Concerning the hot slow cranking speed, if you unplug the distributer and the cranking speeds up, closer inspection of the ingnition is needed. If no change then measuring the voltage drop on the positive starter cable and also the ground path. Anything greater than 0.2 volts DC under cranking load means excessive resistance in the cable. Next test should be Amp draw which may peak at close to 200 amps on initial start command and very quickly lower to something in the 100 amp area. Testing is preferable to parts swapping. That being said a worn bell housing starter bushing is very common problem. David

[Wheelie Pete]

New wire harness often means wrong starter cable. Make sure you have a 6 volt starter cable and not a 12 volt starter cable. 6 volt cables are thicker.