hey, i have a honda civic 97 EK 4 doors, it's been 2 months now that my car is using a lot of fuel 2 days ago i put in 18 liters and i drove 100 kilometers, i put in new spark plugs, does anyone know what the problem is?

 

Tip,

There could be a multitude of reasons as to why your Civic is achieving such poor fuel economy figures. Here are a select few causes for bad fuel mileage on a car:

1. Defective thermostat, causing low operating temperature
   
2. Engine misfire caused by bad ignition wire(s), coil, dist. cap or rotor
   
3. Late ignition timing
   
4. Stuck centrifugal advance mechanism in distributor (this item requires oil occasionally)
   
5. Bad tension adjustment of centrifugal advance springs
   
6. Defective oxygen sensor (causes rich mixture)
   
7. Defective coolant temp. sensor for engine computer (causes rich mixture)
   
8. Worn timing belt (may cause rich fuel mixture in fuel injected cars with a MAP sensor)
   
9. Incorrect timing belt installation (timing marks should line up)
   
10. Incorrect valve clearance (especially if too tight)
    
11. Worn valve guides (makes fuel mixture too lean at low power)
    
12. Vacuum leak from bad vacuum hoses or intake system gaskets (causes lean mixture)
    
13. Dirty fuel injectors
    
14. Bad fuel pressure regulator
    
15. Bad MAP sensor for fuel injection
    
16. Leaking intake duct between air flow sensor and throttle body
    
17. Loss of compression pressure due to worn rings or leaking valves
    
18. Sticking EGR valve (causes rough idling and rich mixture on some engines)
    
19. Under or over inflated tires; worn tires
    
20. Dirty engine air filter
    
21. Exhaust backpressure caused by clogged catalytic converter, muffler or crushed pipe
    
22. Clogged or defective PCV valve

For the latter potential cause for your pool fuel mileage, here is a simple test that you can conduct to determine whether or not your PCV valve is functioning properly:

1) Check the PCV lines and connections for restrictions and leaks.

2) Start the engine and allow the engine to reach a warm idle.

3) With the engine running at idle, using a suitable pliers or fingers, squeeze the hose between the PCV valve and the intake manifold. The PCV valve should make a clicking noise when the hose is squeezed closed.

4) If the PCV does not make a clicking noise:

• Shut off the engine, and remove the valve.
• Shake the valve and listen for a rattling noise:
• If the PCV valve doesn't rattle or doesn't move freely when shaken, replace it and recheck the system.
• If the PCV valve does rattle freely when shaken, check the valve's grommet and hoses for leaks and replace any parts that are cracked or damaged. Recheck the PCV valve operation.

*diagram courtesy of hondapartsnow.com; all rights reserved

 

Take out the spark plugs and inspect, if one is a different color (especially black) than the rest, there is a problem with that cylinder. For example valves not working right or the fuel injector stuck open. If all the plugs are black it's likely a fuel pressure or sensor problem. Are any codes set in the ECU?

 

heyzzz, i removed the injectors and all of them are black, how do i check for codes?
i know where to reset the computer when youre checking you ignition timing.