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Dutch924-racer · Joined: 23 Jul 2007 Posts: 1081 Location: The Netherlands

I have a strange starting problem with my 931 (series 2).

Over the last year I had problems with starting/ cranking the engine.

I had to turn the ignition key in start mode and keep it like that for about 5 to 10 second before the stater starts to turn.

I already changed the startmotor, checked the wiring, replaced the DITC sensor but no result.

Any idea?
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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

924RACR · Posted: Sat Jul 05, 2025 8:52 pm Post subject:

Have you tried replacing the ignition switch? That would 100% be my next/first step.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Dutch924-racer · Joined: 23 Jul 2007 Posts: 1081 Location: The Netherlands

Hi I replaced the switch and it seems to start directly again, many thanks!
_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

924RACR · Posted: Sat Jul 19, 2025 10:39 pm Post subject:

Excellent! Some times we get 'em right!

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Dutch924-racer · Joined: 23 Jul 2007 Posts: 1081 Location: The Netherlands

Unfortunately the problem is back/ still there, any other hints?
_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

Beartooth · Joined: 05 Apr 2022 Posts: 305 Location: Roberts, MT

Sounds like either a wiring issue or sticky starter solenoid. If it's pretty consistent - it'll usually kick off around the same time if you hold it long enough - I'd lean towards the solenoid. Bad electrical connections or switches usually won't decide to work if you just hold them long enough. Still, with any kind of starter issue, cleaning battery terminals, removing the starter and cleaning the interface with the block, and the electrical contacts on the starter will eliminate most potential electrical issues. I also had a faulty ignition switch when I got my car - in my case, it'd fire off, then die when you let off the switch unless you tweaked it just right. There is the possibility of the replacement ignition switch going bad too, but that seems unlikely if it's back to behaving exactly like it was before.
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1980 931 diamond in the rough