1989 honda accord

[gman]

can anybody please help me with this car. i got rid of a 94 grand am 4cyl that would get 40+ mpg on the hwy with my hho set up. the best i got on the honda was 36mpg which i got without hho also. i got the older honda because i thought it would get 50 to 60 on the highway and boy was i wrong. if anyone has any ideas i would really apreciate it. thank you.ps i do not have a map enhancer set up on the honda and am not sure if that is my problem or not, i did have one on the grand am.