Hi everyone, working on getting my 928 running after 23 years off the road. Tried for a first start today and it ran for a few seconds. Super exciting even though I have a long way to go! Immediate issue is with the ignition/starter function. When I turn the key to on, fuel pump may or may not kick on, and starter may or may not engage. When starter does engage, it seems to be working fine. Today the starter turned probably 2 out of every 10 times I cycled the key from off to start. Fuel pumps turned on 3/10 times. Other dash light come on fine, windows work, etc.

I’m not sure where to start diagnosing the issue. Can someone point me in the right direction.

 

Make sure all connections are clean and tight, battery, grounds, starter etc. Possibly a failing ignition switch.

 

I’ll check them tomorrow. Do you think battery connection can be ruled out if I’m otherwise getting power to lights, etc.?

 

No.

With bad battery cables and connections often low amperage functions (like lights) work fine, and higher amperage demands (like starter) do not. Regardless of starter operation, a car like you describe (23 year rest) absolutely needs all ground points serviced and probably a new negative battery cable. There's also a current track of connections through the relay panel to operate the starter...and pretty much everything else, so service every connection in the relay panel too.

It's a lot of work, some of the ground points can be a paint to access, but the rest of your electrical problems (and there will still be some) will be easier to diagnose and fix.

 

get a can of Deoxit 100 to use on every electrical connection,
well maybe two cans Amazon sells it

 

While you're doing that, have you changed the fuel filter and flushed the fuel system?

 

Yes, went through the whole fuel system - ended up replacing all hoses and injectors.

 

Ditto the above. Grounds are critical but so is a good battery with clean tight fittings. Had a similar issue with starter and after cleaning everything ( include the connections at the starter) it turned out to be a bad battery. By that I mean it would take an overnight full charge and show 12+ volts, but was not providing enough amps to reliably start the car. Brand new battery fixed it.

 

Xx