P0505 Code

Hey guys,

I just joined the forums in a final attempt to resolve the issues with my 1998 Civic Ex Coupe. The check engine code is P0505: Idle Air Control. I have tried cleaning the  IACV and when that did not work I bought a brand new one. It seemed the problem was solved because the check engine light stayed gone for a while...until that day. Engine light comes on. The car begins to idle higher and then when I try to start going I really have to give it gas. Whenever I let my foot off the gas the car jerks a little and when I shift and put the car back into gear it also jerks. I have researched it enough to know that it is causing a large loss in power in the motor, causing the rough driving and jerks. I want to know what you guys think the problem may be and how to solve it. Any ideas?

Thanks!  

p0505 is idle air control system malfunction. hold the engine at 3000 rms untill the fans kick on twice let the car idle. next disconnect the IAC connector if the engine speed does not drop or stall replace the IAC. if it does drop adjust the idle and clean the ports on and inside the throttle body. to adjust idle hold the rpm @ 3k until the fan comes on then disconnect the IAC and adjust the idle screw. there is also a port inside the throttle body that should be cleaned as well. you may also have and engine coolant temp sensor problem if that doesnt fix it. check your spark plugs to see if they are fuel fouled if all the plugs are fouled the coolant temp sensor may not be giving the correct reading to the ecu. check for vaccuum leaks and intake leaks. hope this information helps. (Honda Mechanic)  

It helps a lot, thanks! I will try all of that as soon as I get the time.

I had another question. Could a worn TB gasket possibly be the issue? Causing an intake leak, as you suggested.  

I cleaned it and then assembled everything back together and got the idol adjusted correctly, but now the fans don't seem to kick on. I let it run for a while.  

EDIT: They came on, just took a while.  

I cleaned the TB and replaced the TP sensor. Issue still remains. No vacuum leaks. Next will be to check for coolant issues.