engine and drivetrain Weird Stalling Issue

[gmlogmd]

I am looking for a little help with my 2002.  It will just stop running because it stops getting spark.  If I am driving down the road it will just stop getting spark, if it is left in gear it will start up again after a few seconds (suddenly spark again).  Sometimes, just a momentary lack of spark like a hiccup, sometimes it will die at a light, I have pushed it off to the side and turn the key and it starts right up.  I will drive it sometimes and it will run fine with no problems for say 30-40 miles combo Freeway/City.  It has an electronic ignition and that has been check and was given a clean bill of health by Pertronix.   I just don’t know what is going on.

Car Information: 1976 2002 with electronic ignition with a Webber carburetor the timing is set correctly and the issue “is” spark I placed a devise that shows the spark in line from the coil to the distributor and have watched it just stop sparking and die while is idling in the drive way.  I have swapped out coils and that did not solve the issue. 

 

 

[path88]

Well, I can only speak for myself (and maybe this will help others in a similar situation) but I had this happen to me earlier this month.  Very similar symptoms.  Changed the coil, didn't help.  Changed the condenser and now it's fine.

 

I'm running the ignition in "original" mode: points on my distributor.  Same car as yours though. '76 w/webber.

Edited July 26, 2013 by path88

[Simeon]

A lot of people have had reliability issues with Pertronix which cause these mystery issues (but then a lot of people have never had a problem). Sounds most likely a problem with the wiring

Check your low tension wiring well around the coil and distributor . Is your pertronix actually connected to 12v or the reduced voltage from a ballast resistor?

Has it ever run well?

Is the magnet well fitted over the distributor shaft?

Wiring internal to the distributor not rubbing and shorting on anything?

Edited July 26, 2013 by Simeon

[Mike Self]

If your Pertronix checks out OK, try this.  With the car idling (not on the road) try jiggling the ignition key and see if you get a hiccup.  Then try jiggling the wires on the back side of the ignition switch.  The electrical switch part of the ignition switch can wear and the contacts can jar loose.  Since all your spark juice goes throught the switch, a bad one will cause the symptoms you describe.  Another way to tell is if any of the accessories that only work with the ignition on (headlights, radio, brake lights etc) also hiccup, their current flows through the ignition switch too. 

 

Final check.  Look at the car's wiring diagram; IIRC there's a relay in the ignition circuitry; it could be failing intermittently, or even have a loose wire...

 

Hope it's an easy problem

 

mike