Failing ignition switch?
 

Ever since I bought my car, on rare occasions, turning the key primes the pump but the car simply will not turn over. Usually, 3 - 4 tries and it eventually starts. It hasn't done this in well over a year but I just went out for gas and it decided it did not want to turn the engine over after refueling.

I gave it 6 - 7 tries then it started like normal.

Is it safe to assume the ignition switch is dying?

Of course, I get home and test it and it’s working fine. Old cars are fun.

I'm far from an expert but I'd like to suggest you check for an iffy wire connection at the ignition switch OR at the soleniod at the starter.

Do you hear a click (at the starter) when you turn the key to start? Could be a bad ground. Check (clean) the trans, to body ground strap.

No, I don’t believe it’s a starter issue. The car starts just fine 99% of the time. Occasionally, and I mean very rarely, I get literally nothing when turning it all the way to start.

A bad ground like the tranny strap would make sense too.

do you have any alarm in your system?
Ivan

Mine did the same, starter ground cable corroded. That will cause a zero cranking condition, so will an equally bad negative battery cable or terminal connection and affect charging.

Nope.

I'll try and find the starter ground cable. The battery cables are relatively new. Thanks!

Among the other possibilities discussed, this symptom is fairly typical of a starter wearing out. Do you have any idea how old the starter is? But try the easy/cheap stuff first.

One way to check if ignition switch is the culprit is to have heater, fresh air, and/or AC running when you try to crank and get zero response.
If car engine does not start (no crank at all) but the heater/fresh air/AC stops running while key is in crank position, that means ignition switch is good and you can go on with other possible reasons discussed above.

I don't, but my guess would be it was installed back in the '90s when the engine was rebuilt. I can dig through my documents and see if it was replaced since then but I don't remember seeing an invoice for one.

Thanks for this!

So when in the crank position, my ECU emits a "beeeeeep" prior to starting and it persisted while refusing to crank.

My issue is that I may not be able to reproduce the problem for another year!

The more I think about it, the more I'm wondering if the starter is the culprit. I've noted that when it's cold, it sometimes seems like it cranks a hair slow. Battery is new and voltage is fine, so a failing starter would make sense.

I pulled off the key bezel and the entire ignition unit was removed previously at some point as I didn't have the two bolts that have to be sheared off to remove it installed, so it's likely the switch was replaced at some point, most likely in the '90s when the car was refurbished.

main culprit is most of the time the ground cable from transmission to the body....
Ivan

Well, I took it for a spin and she started on the first turn like she has done every time I've driven it for the past 18 or so months.

We'll leave it at "keep an eye on it" for now. I need to throw her on my brother's lift and grease the spherical bushings in the next month so I'll check the tranny ground strap then.

Yeah, keep an eye on it. What happens as the starter wears is the brushes wear down to the point where they are barely making contact with the commutator. Then it will occasionally not start. IF you bang on the starter with a hammer or rock or such, it will then start. That's pretty much a dispositive test for a bad starter. Then it gets more frequent until you get tired of messing with it and replace it. Or you can take matters into your own hands (pun intended) and replace the brushes and get many more years of use out of the starter.

Rebuilding a starter consists of disassembly, turning the commutator to ensure it's smooth and relieving the insulation between the commutator poles, cleaning and re-lubing the bearings, and installing new brushes. You may also replace the pinion gear/engagement clutch part on the nose of the starter. Good for another 5000 or so starts.

If the pump runs then the starter switch is OK. If the starter is not turning then I suspect the problem is corroded contacts in the starter solenoid. I have replaced the solenoid on the starter on my car (1978SC) twice in the last 30 years, last time in 2020. The brushes were absolutely fine, so I left them alone. I've since refurbished the old solenoid following instructions on this forum and keep it in the car as a spare.

So, my advice is change the solenoid (cheap and effective solution) or buy a new starter which of course comes with a new solenoid (more expensive solution). But do this only after you have checked all the grounds.

Roy

I went through this and did every single suggestion suggested above. I drove myself crazy and replaced nearly every part imaginable chasing it down. Same exact symptoms you describe (video!). Finally I found this thread...

http://forums.pelicanparts.com/porsche-911-technical-forum/348306-ignition-switch-inside-fix-start-lockout.html

It may not be your fix, but wanted to throw it out there in case you end up chasing this for years like I did.

I can agree with JSV798 and PeteKz…as contacts do get corroded just from no use and by repeated arc that occurs upon starting. There’s still the issue that no current is getting to the starter which of course could be from the ign switch.
I can’t recall which (analog) car I had years ago, but being short on funds for a new starter I would crawl and reach under and give the starter a whack with a hammer. The solenoid was attached to the starter but couldn’t access it directly but hitttng the starter was enough to get the solenoid to do its job.
Fords used to have a remote solenoid on the fender wall, when they had starter issues you could hear the motor whine if the solenoid wouldn’t engage.

Ditto what Roy said. The solenoid gets worn too

So, naturally, I cannot reproduce the problem.

I really want to take the 2 hour ride to Carlisle in it this year but really don't want to end up being bump started 100 miles from home!