Sticking Starter

[RickKlem]

My 1977 911 has been sitting for a few years due to other issues. I had to replace the fuel lines through the tunnel . Now when I try to start it the starter continues to spin once I release the key. I Have read through some threads here and the problem mentioned is either ignition switch or solenoid on starter sticking.

To troubleshoot my problem, I turned the key to the start position until the starter began turning over , then I removed the key. I unplugged the wiring connector in back of the switch , but the starter continued to spin. I had to unplug the neg side of the battery to stop it.

Then I removed the starter (PITA) , and tested it on my bench. I applied power to the main terminal and then to the spade for the solenoid. The solenoid pushes the starter gear out and starts the motor . When I remove power from the small spade (ignition) the starter gear retracts and the motor stops spinning.

When the starter is in the car and this problem occurs , I have to remove the neg to the battery to stop it , but when I reconnect the battery it does not start spinning until I turn the key again.


Could it still be the starter? Maybe the spring inside the solenoid is not strong enough to pull it back while it is meshed with the ring gear. Both the ring and starter gears look good.

Thanks
Rick

[James Brown]

i would suspect the starter solenoid also. might need some cleaning. Might work on the bench with no load.

[RickKlem]

I took the starter to the local starter shop today and they ran it through several test and the could not make it stick . They said the solenoid had no problem retracting when power is removed from the ign spade. They suggested a low voltage on the battery or maybe ign switch.

Like I said before I have unplugged the main harness just behind the ign switch and it did not stop the starter.

I have 12.8 on the battery and as he suggested , I attached my battery charger while attemtping to start it and it still wnated to continue to run.

Any suggestions? Could it be a bad ground strap?

Thanks
Rick

[NOLAsc]

Mine seems to stay engaged too long on the first start on cold mornings lately. Planning on trying to clean it.

[Howard M]

You might try hooking temporary lead wires with a volt meter to the starter to verify that solenoid power is interrupted when the key is released from the START position. If there is no power (and I suspect there isn't) then the solenoid can't be engaged on its own and must be mechanically "stuck" in the engaged position, thus powering the starter motor, too.

[mede8er]

With the starter out, peek inside the bell housing and inspect your ring gear (gear that bolts around the perimeter of the flywheel)...if it's chewed up it will hamper engagement/disengagement.....

[mreid]

Are you unplugging the main harness or the connector on the ignition switch? You have to disconnect the ignition switch completely. Even if the solenoid couldn't retract the pinion, the starter would stop running. This problem is not the starter. I suspect the ignition switch as this is a classic problem, however, usually the starter starts spinning again once battery power is reapplied. Do you have an alarm in the car that disables the starter? This almost sounds like a latching relay gone bad.

[RickKlem]

Thanks for the suggestions.

I think I found the peoblem to be a bad ground connection (transmission mount ground). I had the transmission support out so that I could run new fuel lines through the tunnel. I had the tranny supported with a jack stand and I had the body to tranny ground strap connected to one of the threaded bolts on the bottom of the tranny. The problem was that this connection was not tight. I decided to reinstall the cross support and install the ground strap correctly. This appears to have resolved my starter issue.

Thanks
Rick