Feckin Starter Motor

[sladey]

OK I’ve reached a bit of an impass and would appreciate comments on where to go next.

Some of you may know my car wouldn’t start about 6 weeks ago - just a click, nothing else. I then found I couldn’t remove it because of how I’d previously installed it so long story short, I took the engine & gearbox out, and while I was in there I changed the clutch, fitted lightweight clutch plate housing, and replaced a load of seals in order to tackle oil leaks, and cleaned it all up (oh and I made a special trolley for carrying the engine and gearbox)

So last week-end it was all going back together nicely. The started that had clicked was replaced with a hi torque one that was sat on my bench that I had tested on the bench.

When it went in it wouldn’t turn the flywheel - it whirred but didn’t turn it. Then it did turn it - probably about one go in 10 turns.

I put it down to a faulty starter, and ordered a new one. I got one from Design911 - a 10 tooth one because that is what was recommended for an 87-89 G50 car (though the previous one had been 9 tooth)

Fitted it Tuesday night. Tried it and it turned the engine a few times but then just whirred......





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[sladey]

OK at this point I should share pics of my main power cable. While putting everything back in I noticed a large blue spot on the main power cable that goes from the battery to the starter motor.



I’d made a mental note to replace the cable or at least part of it. After the problems starting I decided that would be the next thing to do - so I did it this afternoon

Look how bad the cable was


I joined the cable inside the car and bought a proper brass connector to do the job and then insulated it well



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[sladey]

Insulated


And I also put some garden hose around it as added impact protection.




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[sladey]

So I went to start it

The start motor just whirred again - no sound of any connection with the flywheel or turning of the motor.

I checked the voltage drop across the battery terminals - just under 12v. I put a charger on it while I gradually put the car back together.

When I’d got it up to 12.9 volts I tried again - no change - just a whirring sound - no engagement

One odd this about this starter motor compared to other I’ve installed is that the fitting holes were elongated - allowing some movement in the installation position. I’m not sure if I could have installed it too far away from the ring gear? When I went to install it, it seemed to fall into a natural position so I left it there

I’m pretty sure with the new cable it is getting the sort of volts it should be getting now.

Any ideas?

I’m going to have a look at it all again on Tuesday night when I’ve stopped swearing




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[sladey]

Sorry Jason - I felt I needed to give the whole picture before I got round to the actual question.

As usual I’d be grateful for any suggestions


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[jb]

Now the full volts are getting through maybe try putting the old one back that does not have elongated holes?
You don't have to take the engine out to do it or at least I didn't.
Must be mega depressing though.
Go and get a few pints in and try again another time.

[Gary71]

Difficult one. I think you may have to go back to basics and count the teeth on your flywheel.

The cable was an interesting diversion, but probably more prevented a future fire/breakdown the anything else.

Do you have any photos of the flywheel to avoid pulling it out again?

[jb]

I deleted my 'and..' post when I realised you hadn't finished and was dismayed at your next post.
Wait for Jon - he will probably know what to do.
But if the original problem was a click then maybe the feed was the cause and not the motor.
The only time I had the click problem I checked the little fuse box (14?) in the engine bay and when that didn't fix it I got Chris to change the starter motor. A few years later that one started to fail to disengage so I replaced it myself and all fine so far.

[sladey]

I do actually - but I’ve no idea what number suits 10 teeth and what number suits 9 teeth.




When I first installed the hi torque starter I was just told this would fit everything up to 89 - sure enough it did. And it worked for a few years.

I replaced it when it wasn’t working but after the replacement I found I’d got a big battery drain anyway which could have caused that problem.

This time when I went to buy, the perceived wisdom and advice on the design911 site is for 87-89 G50 you need the 10 teeth jobbies


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[sladey]

Now thinking about it - that’s the flywheel - not the starter motor ring gear


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[sladey]

This is the best I’ve got of the ring gear



And here’s the hi torque 9 tooth (on left) versus 10 tooth (on right)




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[Gary71]

I’m hoping someone with the details will pitch up soon to help.

I’m just going to try and count the teeth on the ring gear! But I have been drinking so counting past ten will be hard! Thanks

[sladey]

Thanks Gary - I’m happy to print out and count - but I don’t know what the possible number options are

[gridgway]

If the starter is spinning, then the teeth on the starter are missing the teeth on the ring gear. Either too far away or the gear isn't being thrown out enough. I vote for the latter, but unless you can see what's happening, I don't know how you diagnose! The starter gear must be being thrown out far enough to activate the solenoid if the starter is turning. I'd test it before putting the engine back in.

BTW I don't think that counting teeth on its own will be of much help, you need to work out the pitch. In the picture the new one looks the wrong pitch to me with the distance between the teeth looking too small. But that's a bit of a wild-ass-guess as the merkins say.

Graham

[210bhp]

That 9 tooth looks as though it ‘just’ engaged once at the end of the teeth then gave up. I wonder if position/engagement is your issue?

Regards
Mike