Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
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?

__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-04-2023, 09:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
Of course, I get home and test it and it’s working fine. Old cars are fun.
__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-04-2023, 10:44 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Jan 2017
Location: Canada's East Coast
Posts: 723
Garage
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.
Old 03-04-2023, 11:36 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
pete3799's Avatar
 
Join Date: Nov 2008
Location: Vermont
Posts: 7,431
Garage
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.
__________________
Pete
79 911SC RoW
"Tornadoes come out of frikkin nowhere. One minute everything is all sunshine and puppies the next thing you know you've got flying cows".- Stomachmonkey
Old 03-04-2023, 11:50 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
Quote:
Originally Posted by pete3799 View Post
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.
__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-04-2023, 12:11 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
proporsche's Avatar
 
Join Date: Sep 2011
Location: Bohemia
Posts: 7,261
Garage
do you have any alarm in your system?
Ivan
__________________
1985 911 with original 501 587 miles...807 226 km
"The difference between genius and stupidity is that, genius has its limits". Albert Einstein.
Old 03-04-2023, 12:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Join Date: Nov 2021
Location: The Far Side - Chicago
Posts: 1,203
Garage
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.
Old 03-04-2023, 01:23 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
Quote:
Originally Posted by proporsche View Post
do you have any alarm in your system?
Ivan
Nope.

Quote:
Originally Posted by EC900 View Post
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.
I'll try and find the starter ground cable. The battery cables are relatively new. Thanks!
__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-04-2023, 02:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
PCA Member since 1988
 
Join Date: Feb 2018
Location: SW Washington State
Posts: 4,225
Garage
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.
__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners.

Cars are for driving. If you want art, get something you can hang on the wall!
Old 03-04-2023, 11:23 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Sep 2021
Location: France
Posts: 946
Garage
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.
Old 03-05-2023, 04:13 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
Quote:
Originally Posted by PeteKz View Post
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.
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.

Quote:
Originally Posted by wazzz View Post
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.
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!
__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-05-2023, 05:12 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
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.
__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-05-2023, 05:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Registered
 
proporsche's Avatar
 
Join Date: Sep 2011
Location: Bohemia
Posts: 7,261
Garage
main culprit is most of the time the ground cable from transmission to the body....
Ivan
__________________
1985 911 with original 501 587 miles...807 226 km
"The difference between genius and stupidity is that, genius has its limits". Albert Einstein.
Old 03-05-2023, 07:34 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
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.
__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-05-2023, 07:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
PCA Member since 1988
 
Join Date: Feb 2018
Location: SW Washington State
Posts: 4,225
Garage
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.
__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners.

Cars are for driving. If you want art, get something you can hang on the wall!

Last edited by PeteKz; 03-05-2023 at 02:20 PM..
Old 03-05-2023, 02:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered
 
Join Date: Mar 2013
Location: Manchester, UK
Posts: 465
Garage
Quote:
Originally Posted by MrBonus View Post
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?
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
__________________
1959 Bristol 406 (bought in 1972; sold in 1977)
1966 Porsche 2.0 coupe (bought in 1977; sold 1981)
1978 Porsche SC coupe (bought in 1993)
Old 03-06-2023, 03:09 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
kinda slow
 
shamrok's Avatar
 
Join Date: Jul 2010
Location: Colorado
Posts: 297
Garage
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...

Ignition switch - inside to fix START lockout

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.
__________________
1983 911 SC Coupe
Old 03-06-2023, 07:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered
 
Join Date: Nov 2021
Location: The Far Side - Chicago
Posts: 1,203
Garage
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.
Old 03-06-2023, 08:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
PCA Member since 1988
 
Join Date: Feb 2018
Location: SW Washington State
Posts: 4,225
Garage
Quote:
Originally Posted by JSV798 View Post
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
Ditto what Roy said. The solenoid gets worn too
__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners.

Cars are for driving. If you want art, get something you can hang on the wall!
Old 03-06-2023, 02:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Kind of Blue
 
MrBonus's Avatar
 
Join Date: Sep 2010
Location: Delaware
Posts: 2,308
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!

__________________
1971 911T w/ a 2.7 (ITBs, EFI, a bunch of other stuff, 2180 pounds with fuel)
2024 Ford Bronco Raptor
Old 03-22-2023, 12:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply


 


All times are GMT -8. The time now is 02:12 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.