For some time I’ve been having a problem with the starter solenoid kicking in on my 1980 Euro 928s (five speed). Have to play with the ignition key to get it to kick in. I thought it was the electrical contact part of the switch but after purchasing a new one, the problem is the same. It seems there is too much play in the lock cylinder to get it to move the contact portion to get it to start. If I turn the key and feel the shaft ,the key turns quite a bit before the shaft starts turning. With the contact portion unscrewed from the switch portion, I can use a screwdriver and it kicks in all the time so it seems there is just too much play. So my question is, how do I remove the ignition lock assembly to look at the shaft, etc. I don’t find anything in the workshop manuals (or maybe I just didn’t find it) and it doesn’t seem obvious from a visual inspection.



As an aside, the new electrical portion of the switch doesn’t momentarily run the fuel pump to prime the system.

Mike

 

just did this on my car. the shaft that connects the key lock portion to the electrical portion had worn down ever so slightly not allowing the last hair of travel to engage the starter.

There is a kit that will replace the the old version shaft with the later version cross head shaft. it is longer and requires a spacer and longer screws for it to go back together. I drove mine with the electrical part dangling below my dash for a few months before getting time to swap out and used the screw driver to start it - just remember the key needs to be in and on to unlock the steering wheel.

https://rennlist.com/forums/928-foru...ng-lights.html

 

jwillman,

Thanks, Where did you find the new shaft? Does the cylinder come out after removing the roll pin? And does the roll pin come out from the top or bottom? The only thing I see on mine is what looks to be the threaded end of a screw that just barely protrudes from the top of the case. I'll take another look tomorrow.

Mike

 

I had a very similar problem a while ago - replaced the switch, OK for a while, problem came back. Was actually the starter relay causing the issue.
Moral - check the simple, cheap possibilities first.
jp 83 Euro S AT 57k

 

I got my kit from 928sRUS, new cam pin, spacer and longer screws to hold the electrical part of the switch to the steering column assembly.

Mine had a pin which I drilled out. The lock assembly and cam then pulls out from the front. Easy swap out of new parts and then used a threaded screw as a replacement to hold the ignition switch body in. Sounds like someone may have already been in yours and hopefully you can get the thread pin out.

 

Thanks

 

Hi Mike, read your thread and started sounding familiar what was happening with my '79 RoW in that I also installed both new ignition switch and lock cylinder. Car was not starting by the key and after putting both in, I heard the car crank for the first time in years by the key.
Got other things buttoned up, went to go roll it outside to try and start her up and.......nothing! I had bumped the starter 3-4 times before and it cranked each time, problem solved, right?
Wrong, what I overlooked was the starter ground back in the spare tire well. I had cleaned all the other grounds and didn't know that the starter ground was in one of the two white/clear connectors in the tire well.
I sprayed them both with some Deoxit and pulled them apart and back together several times to try and get a good connection, hasn't failed to start since.
Just a thought.
Bob

 

Bob, Thanks. The new switch portion I received which has the X pattern for the shaft portion of the lock cylinder to fit in to didn't seem to run the fuel pump for a second of so when you turn the key on. Not sure how critical this is as long as all the check valves in the fuel injection system are working. Any experience with this? When I put the new shaft in, I guess I'll have to go with the new contact/switch portion since my old contact portion does not have the X pattern. Or maybe I grind off two sides of the X to make it work.

Mike

 

The fuel pump running on initial connection of the ignition circuit before you start is controlled entirely by the fuel pump relay. All the ignition switch does for this is switch the ignition circuit - which must also work for it to ever start anyway.

Look to the fuel pump relay.

alan

 

Alan, I tried the two different switches several times (using a screwdriver rather than the key) and in each case the old switch ran the fuel pump and the new one didn't. Although I'll admit, I was really more concerned about whether it would kick in the starter solenoid rather than checking to see if the fuel put was running. I just did a continuity test on both switches and they both seem to be identical, so maybe I was just having a senior moment. Car started fine with both switches although I did start/stop it in rapid succession. This is an early S model with mechanical FI, but I don't know that that makes a difference.

Thanks for the reply.

Mike

 

Mike --

The fuel pump relay uses a fairly simple trigger circuit with a couple small resistors and a capacitor used to set the timing requirements. When power is first applied, it takes a second or two for that capacitor to charge. That's the initial pump-run condition mentioned. When you cycle the circuit before that capacitor self-discharges, you won't get that initial pump-run condition.

I'm not sure if the initial pump-run condition is a "bug" or a "feature". The difference is really small; a "feature" is just a "bug" that's documented in a proactive way.

 

Well they made some special effort to do this in the design. If it doesn't work - it only slightly delays the point at which the car would start. We do know there are stock relays out there that no longer work this way (that once did), I believe there are also some after market relays that probably just don't have this priming function - they can still work to start & run the car too.

If you commonly turn the ignition on and immediately start the car it can't provide that much benefit anyway.

Alan

 

Thanks