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starter wont work when engine hot ??

Posted: Sun Jun 10, 2018 8:25 am
by JohnLiles
If have been sat in slow traffic or running at speed for a while , when I switch engine off it wont restart.
Just a slight dimming of ignition light but no noise whatsoever.
Leave it for a few hours and will restart like normal.

Push button start , 12 electrics , 912 motor
Have not searched this yet , but guess something needs replacing or repairing ? :(

Re: starter wont work when engine hot ??

Posted: Sun Jun 10, 2018 9:58 am
by Dan Epperly
JohnLiles wrote:If have been sat in slow traffic or running at speed for a while , when I switch engine off it wont restart.
Just a slight dimming of ignition light but no noise whatsoever.
Leave it for a few hours and will restart like normal.

Push button start , 12 electrics , 912 motor
Have not searched this yet , but guess something needs replacing or repairing ? :(

You might get by with installing a hot start relay. But my experience is that usually means the starter is on it's last legs before it gives up the ghost.

Re: starter wont work when engine hot ??

Posted: Sun Jun 10, 2018 10:06 am
by Thomas Sottile
John check the grounds and all main power connections as metal gets hot it will expand and brake contact.

Re: starter wont work when engine hot ??

Posted: Sun Jun 10, 2018 2:54 pm
by Doug McDonnell

Re: starter wont work when engine hot ??

Posted: Sun Jun 10, 2018 4:01 pm
by Geoff Fleming
Starter bushing needs replacing. My first Porsche would crank strongly when cold but after even a slight warm-up, not the slightest reaction of the starter. Easy and inexpensive fix...of course, I learned the hard way, after Porsche charged me a fortune. As Harry Pellow used to say, "Experience is a hard teacher but a fool has no other!"
Of course, cleaning/replacing the ground cables, etc. also helps.

Re: starter wont work when engine hot ??

Posted: Sun Jun 10, 2018 4:08 pm
by Martin Benade
My first Porsche acted that way due to a bad ground strap. For six months I had to either count on staying where I went for a couple of hours, or bring a friend to help push-start. The bushing seems to be the most common fix, though.

Re: starter wont work when engine hot ??

Posted: Mon Jun 11, 2018 8:05 am
by neilbardsley
I had a hot issue on my 6v car. Worth checking the wiring from the positive battery to light switch and then the ignition switch. Mine had decay badly and was worse when heated up.

Re: starter wont work when engine hot ??

Posted: Mon Jun 11, 2018 8:17 am
by JohnLiles
Thanks for the responses so far guys , have had a look at the thread referenced.

Just for clarification , when the starter wont work it is not even trying to work , there is no movement or noise , you know that you have pushed the starter button and it has operated because the red ignition light dims ( I dont have key start but pre A button start)
The engine is a 912 type , the electrics are 12v , so assume the starter will be 912 type . I might stick my head under the car to examine further , don't like that confined space much so not rushing to do it !!

.

Re: starter wont work when engine hot ??

Posted: Mon Jun 11, 2018 8:28 am
by Vic Skirmants
Starter can not be a 912. Won't fit.

Re: starter wont work when engine hot ??

Posted: Mon Jun 11, 2018 11:14 am
by Doug McDonnell
The reality is that it s usually not one thing. One thing may make it better but not correct. Here is my favorite way to look at the problem. http://www.cyberwerkstatt.com/Members_O ... ooting.htm Could be starter bushing, could be starter itself, could be wiring. Could be your ignition although it sounds like someone has rewired ignition already to try to fix.Even if you replace the starter bushing and it works I have found that every single wire end should be renewed to good copper. When everything is renewed you will never have a problem again. Sometimes hard to get to that point though. A perfect example is my own a few years ago. I completely restored my car including new wiring harness and all ground wires new, etc etc etc. Everything was new or rebuilt. Car would only crank slowly and hard to start. Drove me nuts. I went through the starter troubleshooter and it ended up being the brand new Bosch Premium rebuilt starter. New starter from abcpartswerks.com (see ad in the Registry magazine) and all is well and starts easily. PS every wire end on your car is now 63 years old. Consider having every wire end at starter and battery renewed.

Re: starter wont work when engine hot ??

Posted: Mon Jun 11, 2018 12:03 pm
by JohnLiles
Vic Skirmants wrote:Starter can not be a 912. Won't fit.
Hi Vic , the engine no is 832331 and the transmission no is 62379 . Does that narrow it down ?