I have a real gas problem

i have a 93 hatch and i put a b18a motor in it with a ls computer and my car is wasting so much gas!! with half a tank i only get70 miles its driving me nuts if any on u honda guys might have an idea of what the problem is pliz help me out.

It's for these cars
1986-1989 Accord Aerodeck LXR-S/LX-S (Japan)
1986-1989 Accord EXL-S/EX-S (Japan)
1986-1989 Vigor MXL-S (Japan)
130 hp @ 6100 rpm,128tq @ 4700 rpm
Why would you use a unworthy B motor
Is it a 94-95 obd1 integra ls ecu or older
Does it run smooth all the way up and idle.

its a automatic ls computer and it was out a 94...and yes its rides smooth just wastes alot of gas ALOT! idk what the problem is im going crazy what do u think it is?

1. 93 civic hatch obd1 your trans?
2. 94 integra LS Automatic ECU
3. B18A? engine or B18A1 what car and trans?
Old motor running through Obd-1 wires ecu no codes or they are but can't be read fixed lost signals
Must be your O2's that drops mpg crazy look at that

its a ls auto ecu..
and my car is stick iput a new o2 sensor and i put a new intake air temp and all the codes went away the check engine light is on but it shows no codes..also the car has a mis fire i dont know what it is i put new spark pluges and everything so i dont know

If you have a CEL on, and you can't find a code, either you're not looking in the right place, or your ECU is dead. Try replacing it w/ a known good ECU.

BTW, using a Auto ecu when you dont' have an auto will show a CEL b/c of the tranny not having the lockup solenoid and several other sensors in OBD-1 format.

As far as using serious gas, again, change your ECU to a known good one. It's probably running in closed loop mode, on a base map that isn't getting interaction from the sensors under the hood... therefore, it will burn gas like crap to make sure it's not leaning out... it's also called limp mode, because it's designed to let your car "limp home".