I have a 91 Honda civic the car has 254,000, I had a 1.5 with 84,000 miles on it installed. I have a high idle at start up and between shifting, it surges after warming up. Just this past week it is doing a little jerking as I drive. I do a lot of highway driving. Sometimes it seems like it has no power, it takes time to get up & go. I tried valve cover gasket kit. I disconnected the battery, cleaned the terminals. Now I get a different code, I forget what the code was. I tried fuel injection cleaner, gas moisture remover. No improvement. I'm only getting about 25 miles to gallon. Any suggestions would help. Thank You for your time Stewart.

Thoughts:

. Purge the cooling system of air, by filling the radiator with coolant until it comes out of the bleeder bolt. Air causes all sort of idle problems on Hondas.

. Check for codes--very important.

. Change the fuel filter, if it hasn't been changed in 48 months or 60,000 miles. Your Civic may be starving for fuel at high speeds.

. Replace the spark plugs (NGK only), if they have not been changed in 3 years or 30,000 miles.

. Check the Engine Coolant Temperature (ECT) Sensor. They can waste a tremendous amount of fuel, as can a failing oxygen sensor.