My 2001 accord with a 2.3 Vtec is showing misfire codes on all cylinders. What could cause this. I pulled the plugs and they look good. Plug wires look good also. The car sat about a month without being started. It ran great before that. Now every time I start it it has codes for misfires on cylinders 1, 2, 3, 4. Also has a code that says misfires all cylinders. Please help!

 

Verify cap/rotor does not have condensation/contamination/corrosion inside the cap. Spray with electrical contact cleaner, wipe down dry. WD40 can also be used.
Verify valves are correctly adjusted.
Verify Fuel pressure is correct.
If it only occurs at part throttle then verify the EGR port is clear in the upper plenum.

 

Thanks, I replaced the cap and rotor today and still have the misfire. Could old gas cause misfires? The gas in the car is 2-1/2 to 3 years old. The exhaust smells. Does not smoke at all just smells. I still have a half tank on gas in the car.

 

Yes, 3 year old gas can cause misfires if you didn't add any stabilizer. Surprised that it even runs!

Might want to drain that tank of stale gas.

Or at least add some gas stabilizer and a fresh top up. Then you might want to look into changing your fuel filter and cleaning your injectors. Old gas can turn to varnish and clog up the fuel filter and the filter baskets in the injectors. Not saying that your fuel has turned to varnish, but it can happen.

 

Thanks, Going to try and get as much of the old gas out of the tank I can tomorrow. I am not very good at siphoning gas so not really sure how I am going to get it out though. Once I get fresh gas in the car I will post if that fixed the problem.

 

You can try using some Isoheet. Just pour a couple bottles in. I would bounce up and down on the car to help it stir a bit. lol

 

Camaro, I am like one or two steps ahead of you on this journey. I just posted a thread 'Getting Bad Gas Out." And then I saw your thread. Let's keep in comms on this. Hope we get some answers.

 

Bad gas may have clogged injectors. Check/test the injectors if you can.