Hey everyone, my gf and I purchased an 05 accord ex-l (5spd) with 53xxx miles. We picked it up from Buffalo a week ago and drove it home to NYC with no problems. All of a sudden yesterday the engine started revving/idling high after driving for a couple miles. The cel started blinking and the car wasn't driving the same. Before we purchased the car we were told by the previous owner that the car was sitting a couple months at a time, so he had to replace the battery. No other work was done other than fluids and brakes. What could the problem be? FITV? IACV?

I started the car up this morning so I can drive it to the nearest auto parts store for a free cel check up. The car wasn't revving high when I started it, instead it was hesitating when I stepped on the gas pedal. I got it checked out and the print out says: *Random cylinder misfire detected*. Does that make any sense? The tech told me I should change the plugs and cables which I intend on doing but why would the car start revving high on its own yesterday and today it stopped?

 

Exactly what code was presented? P0300 or other?

Is the missing always present or intermittent?

Spark plugs could be replaced, but I believe Accord uses long life plugs which should be good for 120K miles. There are no high voltage spark plug leads to replace, but a Coil-over-Plug unit can go bad, however that would not cause random misfire (all cylinders). If someone has replaced the plugs w/ inferior plugs, these may have failed. Go w/ OEM replacements.

Generally, idle air control system should not cause missing, rather low idle, oscillating idle, high idle are possible.

High revving might be caused by sensor error; ECU thinks air temp is colder than it is or other sensor error.

You are likely finding out why previous owner sold the car.

I would suggest resetting ECU after extracting all codes.

You will need a scanner to do this.

good luck

 

It started idling again to 3k and drops down below 1k. A friend of mine is convinced it's the FITV. Can someone tell me the proper way to dismantle it? I believe it could be cleaned.

 

The 05 has one idle control valve. Older accords had two different valves (IACV and the FITV).

When the engine is cooled down, remove the radiator cap and see if the coolant is filled to the top. Air in the cooling system can mess up the idle.

You should get the actual code like TexasHonda suggested. It starts with the letter P and has 4 numbers, like P1234. Post the code on here.

 

There is an Intake Air Bypass Valve is similar to FITV. It should only be open when engine is cold. It connects to engine coolant passage and has two hoses attached. One goes to intake duct and other goes to intake manifold near cylinder head. Engine cover must be removed for access.

good luck

 

The code is P0300, the car is idling again up and down.

 

Suggest removing spark plugs and replacing unless they are OEM and show no evidence of fouling. OEM are NGK (1ZFR6K11 or Denso SKJ20DR-M11) plugs.

Has any work been done since purchase? Sometimes a sticking PCV valve can cause idle lope or loss of vacuum from a disconnected vacuum line.

Check coolant level (cold) is full in radiator.

A failed or stuck open IACV might cause loping idle. They usually fail closed (spring loaded).

good luck

 

I'll check the coolant level and the plugs. Any idea why it's misfiring all of a sudden? The car is completely stock.

 

I am not sure. Did you fill up with gas right before this problem started happening? Check the oil level to be safe as well.

 

The gas was filled with 93 octane a couple times already. Oil is pretty clean and full. There's still warranty as well, should I just take it to them?