Author Topic: Oddball Ignition Problem  (Read 744 times)

Offline Rosebud

Oddball Ignition Problem
« on: July 30, 2017, 11:13:55 AM »
Facts: New coil, new 123 Distributer, new alternator, good battery (12.5 volts at rest, 12.9 volts while running), new wiring harness. The ignition switch is a dash mounted toggle switch. It powers up the ignition system and sends current to the fuel pump switch and starter button. Headlights, horn, etc. all have power regardless of the position of the ignition switch. There’s a light labeled “IGN” on the speedo that lights when the ignition switch is in the on position and it goes out as soon as the engine is running.
 
Circumstances: “Rosebud” began displaying an odd, ignition related problem—at least I think it’s ignition related about 2k miles ago after some spirited autocross driving. As I pulled into the pits it began missing and then stalled and wouldn’t start again until I let her rest for 20 minutes or so. I drove 40 miles home without issue and continued to put another 2k miles on her without a problem. I concluded it was probably the coil going bad and running hard on the track as I did pushed the coil over it’s limit. I made a mental note to swap out the coil but was in no rush because the issue hadn’t reoccured.
 
Yesterday after adjusting my carbs I took Rosebud for a test run and again pushed her hard. Soon after, the missing and stalling returned. I let her rest a bit, she started up and the trip home was uneventful. I immediately ordered a new coil.
 
This morning as I gently drove into town, the missing and stalling began immediately. I limped home, stalling and restarting several times. I did however notice a few things that leads me to believe it isn’t necessarily the coil that’s causing the problem.
 
As she begins to miss, the IGN light flickers, so I assume it’s actually an ALT light.
When I turn the ignition switch OFF when she stalls and ON again to restart, the IGN light remains off and the starter button is dead. After a couple of seconds I try again and everything is normal; IGN light on, starter button has power and the car starts.
 
Given the above, I’m thinking the problem might just be a bad ignition switch. The thing that has me puzzled is why it seems to be associated with hard driving (with the exception of this morning’s drive). Anyone have any other ideas?
 
Thanks!
Rosebud
...the sled, not the flower
https://www.facebook.com/PoserMotorSports

Offline Willie_B

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Re: Oddball Ignition Problem
« Reply #1 on: July 30, 2017, 11:22:52 AM »
Just for grins, remove the dist cap and check for oil in the dist. Mine was filling with oil and then running rough.

Online 94touring

Re: Oddball Ignition Problem
« Reply #2 on: July 30, 2017, 11:40:23 AM »
Check your grounds too. 

Offline MiniDave

Re: Oddball Ignition Problem
« Reply #3 on: July 30, 2017, 12:09:07 PM »
Did you get the right coil? 3 ohm vs 1 ohm? You use the 1 ohm with a ballast, you use the 3 with electronic ignition.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline Rosebud

Re: Oddball Ignition Problem
« Reply #4 on: July 30, 2017, 12:38:41 PM »
Did you get the right coil? 3 ohm vs 1 ohm? You use the 1 ohm with a ballast, you use the 3 with electronic ignition.

I'll be checking the coil in a moment. Is this the correct procedure?

"Disconnect all the low tension wires from the coil and put a multimeter across the low tension terminals. 3 to 4 Ohms is a standard coil w/o ballast. 1 to 2 Ohms w/ ballast."
Rosebud
...the sled, not the flower
https://www.facebook.com/PoserMotorSports

Offline Rosebud

Re: Oddball Ignition Problem
« Reply #5 on: July 30, 2017, 12:42:30 PM »
Just for grins, remove the dist cap and check for oil in the dist. Mine was filling with oil and then running rough.
More than simple missing, although I did pop the cap off and peer into the dizzy. Looked fine, thanks.
Rosebud
...the sled, not the flower
https://www.facebook.com/PoserMotorSports

Offline MiniDave

Re: Oddball Ignition Problem
« Reply #6 on: July 30, 2017, 12:55:48 PM »
Did you get the right coil? 3 ohm vs 1 ohm? You use the 1 ohm with a ballast, you use the 3 with electronic ignition.

I'll be checking the coil in a moment. Is this the correct procedure?

"Disconnect all the low tension wires from the coil and put a multimeter across the low tension terminals. 3 to 4 Ohms is a standard coil w/o ballast. 1 to 2 Ohms w/ ballast."

Correct.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline Rosebud

Re: Oddball Ignition Problem
« Reply #7 on: July 30, 2017, 01:05:10 PM »
Check your grounds too.

Yep. Bad grounds can do weird things. Thanks.
Rosebud
...the sled, not the flower
https://www.facebook.com/PoserMotorSports

Offline MPlayle

Re: Oddball Ignition Problem
« Reply #8 on: July 30, 2017, 03:07:55 PM »
Since other things relying on the ignition power are also going out I would be less likely to suspect the coil and be considering a fraying connection to/from the main ignition switch.  Check all connection points of the wiring to/from your main ignition switch to be sure a connector is not loose or the wire breaking/fraying at a connector.


Offline Rosebud

Re: Oddball Ignition Problem
« Reply #9 on: July 30, 2017, 03:28:11 PM »
Since other things relying on the ignition power are also going out I would be less likely to suspect the coil and be considering a fraying connection to/from the main ignition switch...

That's what I was thinking. I initially suspected the coil because the problem first arose after a track day, then again after another short WOT session. But a faulty coil wouldn't explain why the starter button would be dead following a miss & stall event—but a bad ignition switch would. Will advise. Thanks.
Rosebud
...the sled, not the flower
https://www.facebook.com/PoserMotorSports