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Car runs rough when cold

Hello all,

I purchased a used 1997 Honda Accord 4 door EX V6. At first the car ran fine. After months I noticed that if I didn’t warm the car for several minutes, it will run a little rough for a few miles (3). Once the car was warmed up it ran great. I live in a hot climate.

The symptoms include almost a misfire, rough performance, lack of power. I changed the oil, check the plugs and put a new air cleaner, rotor and distributor cap. This improved the overall performance of the car once it is warmed up. I checked the resistance on the plug wires and the range from from 7k Ohms to 17k Ohms.

What could be causing this poor performance when cold?

Thank you for your time.

You may have a faulty engine temp sensor which could be sending the wrong signal.

Instead of sending a ‘cold engine’ signal, it may be sending a warm/hot engine one not allowing a proper mixture of fuel/air for a cold start/warm up.