what could lower mileage on f22b5 accord coupe ES ?

hi, im having a problem of very low mileage. about 18L/100km (13 MPG) in city driving.
i have changed timing belt, engine oil, transmission oil, oil filter, air filter, fuel filter.

no ECU warning codes, no leakage, no fuel smell from exhaust, nice smooth idle, nice engine sound, normal power on wheels.

what should i check or do to start getting to the problem solve?
the car is accord coupe 2.2i ES 1997 f22b5 non-Vtec SOHC
please help me out

Winter will affect your fuel consumption, and like me, I'm assuming you're in Canada since you used l/100km... although 18 is far too high.  I would suggest cleaning or having cleaned the throttle body... but thats about all I can think of right now... more will come to me because I have had a similar problem.

My best advice and hardest to follow would be to stay off the accelerator ! lol but i think eveyone has that problem !

Have you checked your plugs?

My intial thought as well.... spark plugs, wires, cap and rotor, ensure that you are getting a clean consistent burn.... stay with NGK spark plugs too....

Also driving style, warming up an engine sitting in the driveway, time idling in traffic, low tire pressures, state of tune (mentioned above), brakes not releasing completely, and fuel brand come to mind (some seem to yield better mileage than others).

im in europe, Latvia and its ~ +5C here so not realy a winter.
spar plugs are next on my list. and im definetly gonna go with honda recomended NGK.
what i was thinking was about those sensors and valves. like oxigene sensor, exhaust gas recirculatin system valves (EGR). im not familiar with those sice my previous car was 86 lude, but could thos be the ones lowering mileage?
thanks in advice

Automatic or manual tranny?

18 liter/100km is only about 13 mile/USgallon so that's surprisingly low.  State of tune would have to be pretty bad so you'd notice it running badly.  EGR should also be noticeable.

Dragging brakes would be noticeable by one or 2 wheels getting VERY hot.  And you'd probably notice the drag if you coast the last few feet before stopping.

How common is gas-station fraud over there - maybe you're not getting as many liters as you're paying for??

How about a flaky odometer?  Can you check it against km-markers on the highway?
 
ps... couple more things to check & rule out.
 
How about spark timing?  Retarded spark timing would produce serious loss of power while still being smooth & maybe 'feels' like it runs OK.
 
How about camshaft timing?  How long ago did you change timing belt?  Are you sure it's timed?  Take off upper timing cover & check whether it's still OK.
 

thank for advice.
the new numbers are 15L/100km (15.7 MPG guess i calculated this time right) in 90% city driving. its after all filters change and timing belt change. still havent checked the spar plugs and spark timing, also havent rechecked timing belts position.
im not so sure now about the power, because i have nothing to compare, its definetly slower than my lude, but thats how it should be.

car
Accord coupe, 1997, f22b5, 2.2L SOHC non-vtec, auto tranny

im still getting 18L/100km (13MPG) in 100% city driving.
i now have also spark plugs changed. please help! what should i do ?
how can i check for right mixture?

Could it possibly be clogged fuel injectors?  Have you run a fuel system cleaner through the car yet?

im not sure i get what you meant. how can i do that?

He means a fuel-injector cleaner (solvent) that you pour into the gas tank.  Chevron Techron, or several other brands here in USA.  I don't know what's available over in Latvia.
 

Or something like seafoam.  You pour it in the throttle body throat, the gas tank, and oil crank case.
Here's a link: http://www.seafoamsales.com/motorTuneUpTechGas.htm

miks, i dont know how much you will be able to improve it....     Was it you that said your car was 150hp?     If it is that means your car is just dumping more fuel into it in general after all it doesnt have vtec for the whole gas economy, granted yeah it shouldnt be as bad as 13mpg but it is in city with a more agressive cam so I can understand why it would be that bad,  Have you driven a full tank highway at about 120kph?

yea my car is 150hp non-vtec, but its mileage should be ~18-19MPG in city (one friend has the same engine on wagon chasis).
mileage is bad also on highway 23MPG at 60mph cruising (it should be more like 28-30).
ill try that cleaner.
although i already emailed the dealer for a full engine diagnostic posibilities.

how about all those air meters, o2 sensors and lambda zondes?

Well, if thats what all the information says your mpg/kpl should be then ignore what i said,      as for the o2 sensors,  those being defective could cause that drop,  but those are also not cheap and you should resort to replacing those when youre absolutely sure they are bad. 

i checked the repair manual for O2 sensor response monitoring. ill do that when ill be able to get under the car for connection.
i already checked the cost of it, ~150$ at dealer, 50-100$ on ebay. pritty high pay for such a little knob