Yesterday I drove the 1994 Geo Metro I recently purchased used from Indianapolis to Kalamazoo and back (about 400 miles). In addition to a high oil consumption rate (about 1 quart every 100 miles) I encountered a nasty problems. The plug closest to the fan belts missfires when I pull a grade on the freeway. It does not happen all the time but when it does I have to pull to the side. Sometimes I can shut the car off and restart it and the problem goes away for a while. It seems worse when I am low on oil.
I changed the plug and all of the wires. Does anyone have an idea what could be wrong? Please understand that when it comes to driving to work every morning (about 5 miles commute) the car is perfectly reliable. I only get the missfiring at freeway speeds while pulling a grade.