Starter problem: intermittant no crank
 

My car is a 1977 911S with a 3.2 conversion. During my last track day I had an issue with the car not starting. This is the first time since I've had the car that I've experienced this problem and it worked fine for the first six of seven sessions at the track.

The symptoms: Starter wouldn't crank but I could hear the solenoid "click". This usually means a weak battery or bad connection somewhere. In a hurry to get to the starting grid I push-started the car and it ran fine. After shutting down the car wouldn't start again on its own without another push start. During the two hour drive home there was no generator light on the dash and the lights and all electrical worked fine. After I let the car sit for an hour or so it cranked with enthusiasm and started right up normally.

Troubleshooting: I removed, checked, cleaned the battery terminals and the electrical connections at the starter motor and all were clean and tight. The battery itself is strong and has always been kept on a battery tender during times of low usage.

So I suspect the starter or solenoid may have gotten overheated at the track? Has anyone had a similar problem with a starter. The starter on my car is the original 77 starter I believe. Could the infamous 3.2 DME relay cause a no crank situation or is that a crank-but-no-fire situation?

Right now I'm unsure how to test the starter or solenoid since it works most of the time. Also a little reluctant to take the car on a long drive or back to the track until I figure this out.

I have read, and personally experienced, the issue you are describing. I only experience this issue on days over 90 degrees combined with very spirited driving. You only need to let the starter cool for a short period, and it will be OK.

Of course, it could also be a dirty connection...possibly the hot wire to the solenoid. Worth a check.

I think the DME failure gives you a crank/no start. Sounds like the starter/solenoid. You could try the age old trick of reaching under there and giving it a whack and then trying it. Also carefully check the voltage at the starter during a no crank and see if you have a huge voltage drop. I'd make my connections and then get out from under there to test. Should see at least 9 or so volts even w/ load I think. These things do give out as I have had to replace mine after similar intermittent operation. Ken

This is a common issue. The starter gets hot from a track session and the bendix shaft jambs from the heat. You can live with it like you did or replace the starter. The starter can be replaced without removeing the tranny but it's difficult. The top nut is hard to get to. A partial drop would probably make it much easier.

-Andy