Mitsubishi Repair: Stalling and rough idle, spark plug wires, timing belt replacement


Question
2000 Mitsubishi Mirage, 4cyl 1.8L FI, Automatic.
My car for the past couple of months has been losing speed while driving at a constant speed on the interstate. While sitting at lights/signs, the car idles rough. Recently, while coming off the interstate and to a 4-way, I applied the brake, the car choked and jumped. Then I applied the accelarator and the car stalled. However, it starts back up and drives fine for awhile after. I've had the fuel filter replaced the air filter replaced, the hoses checked, the transmission, alternator checked. My battery has an acid build up. But I don't feel that that would make my car stall. None of these symptoms triggers the check engine light. I know the light is working, because I had that checked as well. Please help.

Answer
Nicole,
Corrosion build-up on the battery terminals can indeed cause problems like stalling and hesitation, so it's a good idea to clean that off.  But your problem could be stemming from bad spark plugs, bad spark plug wires, worn out distributor cap, and/or worn distributor rotor.  A clogged PCV valve can also cause this problem.  I would recommend having those items replaced if you have not had those replaced within the past 36,000 miles or 3 years.  Also, if your car has gone more than 60,000 miles since it's had a timing belt replacement, you should consider having that done.  Most any mechanic can handle replacing the spark plugs and other related items, but if your having the timing belt replaced, have the dealership do it.  
Good luck!