Toyota Repair: 96 geo prizm, geo prizm, spark plug wire set

Question
Hi Ted,
 I just bought a 96 Geo Prizm for my daughter, which I was told had the
same engine as a Toyota. The car has 91k miles. When in drive the car seems
to "lunge" or "hiccup" when it reaches a speed over 40-45mph. It seems to do
it constantly around that speed and above. When I put it in 2nd gear and take
it up to that speed it just revs up high, but doesn't have the same "lunge" or
"hiccup". I was thinking it might be a transmission problem of some type, but
I don't hear/see high revs or it acting like it's having problems shifting. Any
ideas or suggetions on what it might be, or if we continue driving it will it
become worse or unsafe?

Answer
This may be nothing more than an electrical misfire, unless you have already done so, replace the spark plugs, the spark plug wire set and the distributor cap and rotor, at the same time when the distributor cap and the rotor are off remove the coil cover and inspect the coil for any cracks or burned through spots, this is kind of a common problem on these models.