Honda Repair: Throttle sensor, timing, rough idle

Question
i recently had my 93 honda accord in the shop to have some work done. I had the timing done and a complete tune up. when i got it back it was ok for a day or two. but then i started feeling a vibration in the engine when i am driving. it usually happens when i take my foot off the gas pedal, or when i start it up. the mechanic says that the throttle position sensor is what is causing it. i want to know if this is true and can this be changed out myself. it seems to be getting worse the more i drive it.

Answer
Tim, the throttle position sensor (TPS) would not be causing a vibration in the motor. In my opinion that would be the timing. Or a detached spark plug not making a positive connection to to the spark plug wire or the distributor cap itself. Considering your Accord is a 4 cylinder it would only be running on 3 cylinders. Which would cause a rough vibration. Tune up should have been spark plug wires, spark plugs, distributor cap, and a rotor. And a fuel filter. The timing is very easy to mis dial as well - which could cause a rough idle as well. Perhaps being off timing by a tooth or 2. Distributor should have been set and checked to Top Dead Center (TDC) as well as the #1 cylinder. Then timing set. Hope this helps you.