I crashed my 03 accord and its been sitting for a year. I finally gathered up the money to fix it and I purchased a new battery and started her up. She runs fine for about 30-60seconds then the motor revs up by itself to 2k rpm then it drops to 1k and basically keeps jumping up and down. I have a code scanner and it said something along the lines of the Intake system having a Large leak. I took off the intake and cleaned it up, cleaned the trottle body and checked all the vacuum lines. Everything looks fine. IDK what it is? I don't want to start buying sensor and it not be the problem. Has anyone run into anything like this?

 

You should post up the code that you got. It will be P####. That will help narrow down the problem.

 

P0507 and P2279 I believe...I'll double check in a bit.

 

^^^!!

 

Both of those codes point to the Idle Air Control valve. You should make sure that the coolant level is at the top of the radiator. Any air in the system will screw up your idle, so bleed any air out of the system.

On older accords there is a valve on top of the thermostat housing. Open the valve an allow all the air to spit out until a steady stream of coolant comes out. Then top off the radiator.

The valve itself may be stuck, so cleaning the IAC with throttle body cleaner may fix the problem.

 

No bleed valve on a 2003, since the thermostat is fairly low. On mine all the air pockets seem to collect at the radiator cap where they're easy to remove.

 

Since it sat for a year, i double checked all the fluids. Everything is full and fine. Which is the IAC? Where would it be located?

 

It's #1, bolted to the underside of the throttle body. These days Honda calls it a "rotary air valve".

 

Well, I took the entire throttle body off today. Clean EVERYTHING. The IACV was removed and cleaned, I checked the manifold and it has no cracks. I put it together and the BS still remains. I give up. I know its something simple and really stupid and it looks like i have no choice but to take it to the dealer and get raped. I called them and the IACV is $120. Im going to try and find that POS at a junkyard first. Hopefully thats the problem.

 

Check PCV valve and hose. A PCV stuck open or cracked PCV hose might cause this problem (massive air leak). Also check the vacuum booster line for leaks.

IACV can be easily tested w/ battery voltage. It should open w/ voltage and spring closed.

good luck