Need help and suggestions please. Car is 100% stock. I drive slow, shift under 2k, coast whenever a stop is coming up, keep tires inflated to max, etc. All the "good" mileage increasing driving techniques. Yet I'm only getting 33mpg...and that's on the highway!!
The only reason I bought this thing is because it's supposed to get 50-60mpg on the highway.
Carb tends to bog a little when cold, so I'm thinking of starting there (with a rebuilt unit).
You could also change the oxygen sensor- should only be about $20.
Check to see if a brake is dragging- does it roll easily on a flat hard surface?
My 87 Civic 1.5 carb bogs too during the first 2 minutes of running on a cold morning, but my mpg is pretty good. You can bend some tangs on the choke linkage to make it pull off sooner. You can check the float level in the carb by looking through the little glass window on the drivers side of the middle part of the carb- you can adjust it easily with the screw on top of the carb.
Someone may have swapped in a different engine... Is you valve cover plastic or black metal? The non-HF engine valve cover is black painted steel and says "12 valve" on it.
Check your timing too and make sure your vacuum advance diaphragm isn't busted (mine was)
Does it have plenty of power? Does it idle smoothly when warm?