Wheat-dogg's World

My otherwise trustworthy Geo Metro has been sidelined for a month, because I suspected terribly expensive repairs were needed. Instead the problem was something very simple, and I feel damned foolish.

We were driving the short distance to the local Jay C supermarket one day when the Geo just quit running less than a mile from our house. It had done this before, and would usually start right up again after sitting for a while. So we got a lift to the market and back home, and let the Geo sit alongside the road to cool off.

After waiting a reasonable length of time, we walked back to the car, started it up and drove it home.

The next day, it refused to start. With a shot of starter fluid, the motor would run a bit, then die. OK, I said to myself, it’s gotta be something in the fuel injection system: bad pump, bad injector, bad electrical relay. The next chance I got, I checked the car for the obvious, John-can-fix-it items in the fuel system.

The pump was not the problem. I could hear it whine when I turned the ignition on. There was fuel pressure in the lines — fuel squirted out when I loosened a fuel line clamp. The pump was OK, and so was the relay then. Next, I checked the injector. This little guy turned out to be a challenge to remove, not because it’s hard to reach, but because the factory puts thread-locker on the mounting screws. None of my screwdrivers would turn the screws, and I was afraid to strip the screwheads. In the end, the only solution I had on hand were a pair of ViceGrips. Not elegant, but effective.
The injector, it turned out, was also OK. It was clean as a whistle and its electrical resistance was within factory specs. It smelled like fresh gasoline, so clearly it was doing its job.

At this point, I decided it had to be an expensive repair, and I would have to admit defeat and have the Geo towed to my mechanic. (Smith Import Car Service, for you Louisvillians out there, does terrific work at fair prices.) Trouble was, I didn’t have the cash, so the Geo sat in the garage while my bank account recharged itself.

Since the car was going nowhere, I figured it would be a good time to take care of a few routine maintenance issues, like changing the spark plugs and replacing a bad tire. I bought the plugs a couple of weeks ago, but didn’t get around to changing them until yesterday.

For the non-gearheads out there, spark plugs ignite the fuel-air mixture in the cylinders by sending an electrical spark across two electrodes. Electricity does not need wires to travel around. Air can also carry electric current. In a spark plug, the center post has an electric potential several thousand volts higher than the base of the plug (the ground). If the gap is set to factory specs, or close to it, the potential, which is analogous to air or water pressure, is high enough for the electric charges to jump across the electrodes. If it’s too small, you get a weak spark (the charge doesn’t build up enough “pressure” before jumping). If it’s too big, the spark is either intermittent or non-existent (there is not enough “pressure” for the charges to jump the gap).

For my Geo, that gap is supposed to be 0.39 inches. When I pulled the plugs out, their gaps were too large for my gapping tool to measure! The center electrode was worn down to make a gap easily twice the factory spec! It ‘s a wonder the car started at all, much less ran as well as it did.

Feeling somewhat abashed for ignoring for so long one of the cheapest and most obvious solutions to hard starting, I gapped the new plugs, put them in, and lo! the car started right up.

Doh!.

You can stop laughing at me any time now.