Rep Power: 0

ok ive been working on my wifes car trying to figure out this damn idle surge. i replaced the MAP sensor i replaced the ECT sensor i replaced the IACV i replaced the TPS sensor and still surging i also drained radiator added new coolant and burped it can anyone tell me what else it may be ? any help will be much helpful thank you.

 
Rep Power: 511

Check for any vacuum leaks?

 
Rep Power: 0

i did that and i cant seem to find any how would you suggest on checking i just pulled the vacuum lines off and checked them out for cracks

 
Rep Power: 222

Fill a spray bottle with water and mist all the lines and connections, etc. If the idle changes when you spray a certain area you've found a problem.

 
Rep Power: 149

Is the EGR valve leaking at idle or maybe the passage ways are all carboned up? Was that IAC valve over $300?

 
Rep Power: 0

Did you check the PCV valve? My 2000 civic was surging and threw a P0505 CEL code. After pulling my hair out, it turned out the be the &%#%'n PCV valve. This is a cheap fix if you do it yourself. Use ONLY a HONDA PCV. I had a new aftermarket one and the HONDA one fixed the issue.


IMPORTANT NOTE: The PCV is a bear to get to. You will need to pull the oil filter and there is not much room to get your hands in there. There is a rubber hose about 2 in. long that attaches to the PCV. You will see that it has a slight bend in it. Well when I put mine back I forgot which way the bend was and I got the P0505 after a day or two. The problem was that if the bend is not correct, the PCV does not seat properly and leaks (ever so slightly but enough to throw the CEL). I put some silicone to prevent any leaks and the P0505 has not come back on.