I just picked up a 00 EX with a broke rod. Replaced with a 94k mile engine from a 98 EX so I had to swap intake manifolds etc. Now when I turn the key on the IACV clicks/buzzes constantly with just the ignition on. If I unplug the harness the buzz goes away and the fuel system kicks on. But the car will not start , I did get it started once but now it won't fire again, just cranks.

Will the IACV being unplugged keep it from starting ?

I've swapped another IACV from a buddy and it does the same thing. I checked the voltage at the connector, one wire is at 12v like it should but the other is showing 10.50 , its hard to tell which wire is doing it the because on the outside of the terminal the wires are side by side horizontal and on the inside of the it its made vertical., if my description makes any sense. With voltage at both wires is that mean a short?

Any help greatly appreciated, I will check back often to reply to any questions. I'd just like to hear the engine run before i start replacing sensors etc.

 

The IACV being unplugged can keep it from starting. Are you using the original one that came with the car or the one from the new motor?

 

Check whether some of your sensor connectors are swapped. Any CEL codes?

 

if you push the gas when starting the car it will start without an IACV. But it should stall when you let off the gas (unless your computer is set to be able to run without the IACV like mine is). Are you sure that the IACV is what is making noise and its not the Main Relay?

 

Fixed it guys, it was a ground on the thermostat housing that I missed on the install, runs good now.

 

^^haha same happened to me. car would not start without that ground. and for the IACV its supposed to make that humming sound