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Ignition systems: what's the point?

A lot of motorists these days weren't even alive when new cars still had distributors with points, carburetors and manual... well, everything. I bet if you stop 10 people and asked what "ignition" refers to (especially those that drive an electric vehicle or hybrid), most would say ignition was an R. Kelly song, start up fund or something that happens when lighting a fat one.

Pontiac GTO distributor diagram

 

But if you're driving an old car, like a 1968 GTO, things like your spark plugs or distributor points are critical components of your ignition system and things that you need to check periodically. This task isn't easy, and fewer and fewer people every year are capable of doing this maintenance as newer cars have electronic ignition systems and other inventions that require less maintenance.

I took my goat out for a spin a couple of weeks ago, and when I got back in the car to leave my favorite local craft brewery, it started (ignition!) but it wouldn't stay running (no ignition). Every time I had to stop the car at a stop sign or a street light, it stalled. The engine also had a hard time revving to higher RPMs and was unresponsive to my attempts at mashing the accelerator. I made it home but had to push the car in the garage after I "inadvertently" flooded the engine.

Time for some maintenance

The first I did was call my Pops. He asked "when was the last time you checked the points?" "The last time you and I serviced the distributor", I said. This was 10 years ago or more, and was a job that we did together. We pulled the distributor from the car and rebuilt and replaced a number of old, worn out components. We checked and adjusted the points and the timing. My Dad has the tools of the trade, like a timing light. This wasn't something that I wanted to do on my own this time (Mom and Dad live in California, and I'm in Texas now).

So I did what any troubleshooter does: I started from the top down, testing and analyzing the easy things to troubleshoot, that might cause the car to not start and not stay running. Did it have gas? Yep, the tank was 2/3 full. Was the fuel tank able to breath (e.g., were vapors able to exit the breather tube near the tank neck, so that air wasn't getting trapped in the fuel lines?). Yep, no vapor lock here. Let's pull the spark plugs and check them for dirt, oil, gas, poor gaps or anything else that would prohibit proper sparking. 

Oh snap... problem #1 diagnosed: the plugs were fouled and still wet with gas (remember, I flooded the engine like an idiot). So I cleaned the plugs with carb cleaner, checked and reset the gaps to the appropriate .030" and reinstalled. 

Next inspection: the plug wires and distributor. So I pulled the plug wires from the distributor cap. Note that when doing this, make sure to mark (or to understand, like through a diagram) the position of the plug wires. 

The plug wires were fine (these were replaced when I did the last ignition system service). Inspection also included the ignition coil wire that connects ignition coil to the center of the distributor cap.

Something's not right here. The wire too easily came loose from the cap, and was frayed inside. When peering into the cap, you can clearly see that the wire was fried inside the cap (you should be able to see the copper connector like in the plug inlets next to it). There is no way that a proper electrical current could be sent from the ignition coil to the distributor (and then eventually to the spark plugs) with a connection this poor. 

So I went to my local O'Reilly and picked up a new distributor cap, rotor and ignition coil wire, convinced that this was the issue. When I got home, I reinstalled the spark plugs, installed the new distributor cap and then connected the coil and plug wires. I decided not to check the points, as this would require additional work and likely pulling the distributor. And after all, the timing could be adjusted using the small door on the distributor cap if needed. Things looked clean under the cap, so let's give it a shot!

Crank, crank, crank, crank... we have ignition again! After a test drive, no more stalling problems and normal acceleration again. Sometimes, a basic tune up and understanding of how your ignition system works is all that's needed.