1994 Geo Metro

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.

As I tell everyone... Do a tuneup if anything does not run right. New plugs, wires, dist cap, and rotor. Also run fuel injector cleaner through it, and clean the throttle body out. And then let us know how it runs.

Burning one quart of oil every 100 miles would show up as blue smoke out the back. A bad PCV valve could also allow you to burn oil, start with this ( full tune up) as previously stated and seen if anything looks out of the ordinary( eg oily plugs, oily PCV, etc.) If you still have a problem, do a compression test on the motor and compare the readings between the cylinders. Do a dry and a wet test to see how much the values improve. Wet test is when you squirt oil into the cylinder and then to a compression test. The value will increase slightly, this is normal. But if it jumps a large amount, most likely there is wear( bad piston rings, cylinder wear, etc.) This test will tell you the general condition of the motor. The compression readings should all be basically even with no two cylinders values being off more than 20 %. If these check out, the engine probably doesn't have much wear and it is the valve stem seals which are leaking-making you burn oil.