The Roadmaster: 02. Ignition System
Completed:
Change spark plugs
Change distributor wires
Change distributor cap and rotor
Check ignition coil
Up Next:
Check if injectors send enough fuel
Check vacuum lines
Replace Manifold Absolute Pressure sensor
Whack starter to see if it’s just seizing up
I have the Roadmaster parked in my brother-in-law’s backyard, and this winter conveniently brought snow every weekend for a few months, so I haven’t gotten as much done as I’d like. However, I did finish off the first system I wanted to tackle, which all started with putting in new spark plugs.
The old spark plugs showed a lot of corrosion, though not much wear on the actual spark gap
Since the car is struggling to start and has an irregular idle when it does, I figured a good place to start was to put in new spark plugs. As I pulled the old ones, they didn’t look so worn or scorched, but they looked old and a bit rusty. Until I got to the last two plugs. When I pulled the boot, the whole contact pulled out of the spark plug in a crumbling mess. I decided I’d replace the whole set of ignition wires. When I unplugged the wires from the distributor cap, I found more corrosion. Took the cap off, and sure enough, the rotor was corroded too. I decided to replace those two parts as well. Chasing the rot further, I checked the ignition coil by testing the leads with an ohmmeter, according to the recommendations of Mr. Haynes. It looked like the coil was working, and connections look good, so I paused there on this line of replacement.
Replacing the distributor cap and rotor required a little bit of forethought, including numbering the distributor cable boots, and marking the direction the rotor faces so it gets replaced in the same direction. I put it back together simply enough, fed the intake some starter fluid spray, and success! The engine fired a few cylinders till the starter fluid ran out. That told me that I got spark to my cylinders, and I called that a good ignition day.
I didn’t take the time to get a good check on the injectors to make sure they’re working, but they were several months ago, so hopefully that hasn’t changed. I think the remaining problem keeping me from turning over is due to fuel though, which could mean a problem with the fuel pump, filter, or injectors. That’s my next problem to figure out. If that all works fine and I’m still having trouble, I’ll chase after the vacuum system. I know I have at least one vacuum line coming out of the intake manifold with a big crack, and I know the MAP sensor is a common point of failure, so I’ll probably be addressing that sooner than later. Last of all, I’ve been energizing this whole venture with a battery that I don’t keep very well charged, which means I don’t get a lot of starter energy. I need to also consider the possibility the starter motor needs replacing, if not just a good whacking.
