Code 14, idle surges

[Sarthos]

I've finally started my car after leaving it sit all winter so it wouldn't get any more rusty (thank you MN roads for all your salt). I used the time to get the 11" front rotors, MSD coil, intake manifold, injectors, etc. Now that I've got it all on though, I'm having a problem with the idle surging between about 1000-1500 RPMs and the CEL light comes on with code 14, Intake Air Control. I'm not sure if the idle problem is caused by the IACV or if they're two separate problems.

This has been somewhat of a PITA for me, I didn't realize that the JDM manifold would be harder to use than the USDM one. I have no FITV on the manifold or throttlebody, and the IACV is not plugged in because it has a 3 wire oval shaped plug, and the factory plug is 2 wire. Also, the stock IACV will not fit in place of the JDM one. So, would the fact the IACV isn't plugged in cause the car to have a pulsing idle? Or is there a vacuum leak separate from the IACV problem? I do know that I tried unplugging individual components like the cruise control or the rear motor mount or even the MAP sensor from the intake manifold and they didn't affect the idle at all. I also capped off their vacuum ports and that didn't help either. So I'd guess it's a vacuum leak somewhere, but I don't know how the IACV could affect it, like if it's unplugged maybe it'd act like a vacuum leak anyway? I also removed the EGR, but I don't think that'd cause a problem. Maybe I need to just start taking the manifold apart and putting RTV sealant on every surface where I have a gasket?

Anyway, does anyone know if there is any way to make the 3 wire IACV plug work with the 2 wire harness? Or should I just put a block off plate over the IACV? And do I need to be looking for an additional vacuum leak to fix the idle problem? Or is the IACV gonna be the source of the problem? Or the fact that I've removed the EGR?

[wed3k]

looks like a vacuum leak that would cause an elevated idle. on a good running car, unplugging the iacv would drop the idle.

yank the intake tube off and while running begin to cover up the holes within the throttle body (pre butterfly) if the idle drops then the iacv may be stuck open or the fitv is leaking air. (unless the jdm doesnt have a spot for the fitv, thought they used block off plates?)

to use a three wire, going to need a wiring diagram for the jdm iacv.

[Sarthos]

There is no FITV on it, nor is there a place for one. Is there any good way to find the leak? All the vacuum ports have been plugged. Everything has new gaskets.

[wed3k]

i suspect your iacv is a different design and it may be open. did you cover up the holes inside the throttle body and see if idle changes?

[Sarthos]

I covered one hole and it did help some. There was a lot of suction coming from that hole. Do you know if there is a second hole inside the throttle body? I thought I saw 2 but now that the throttle body is on I can not see a second one. Do you know the best way to permanently seal the hole's or would that create more problems. Lastly, yes the iacv is a very different design.

[wed3k]

okay, your best bet would be to hook up the iacv. you'll need a wiring diagram for that iacv and the pinout for the ecu. im assuming you're running the correct ecu?

anything usdm accord related, i have the wiring diagram so i can help you with that. make sure the throttle plate is all the way closed.

[Sarthos]

I have the stock ecu for my vehicle. I have the entire wiring harness for the manifold from the other vehicle. It is a 3 wire iacv, It is JDM not usdm. So, I don't know if a usdm diagram with help. Do you know where I might be able to find a diagram for JDM? Otherwise, do you know how I might be able to properly delete the iacv?

[wed3k]

unfortunaly the usdm ecu wont work since it is only designed to control a two wire iacv. i dont know how to get rid of the CEL of the iacv but you can take it off and get a block off plate for it. use the idle adjustment screw for your base idle but if you have anything that puts a load ie: powersteering, a/c, sound system then you'll need a iacv or just anticipate it by keeping the idle high.

[Sarthos]

Thank you for all your help.
Is there a tread for how to reroute the coolant lines?
Right now I don't have access to the internet. My mom has been posting this for me because I am without internet service right now.

Couldn't I put a resistor at the end of the plug, for the iacv = to the resistance of the iacv? If I measure it with a DMM. Would that disable the CEL?

[wed3k]

that could work, if the iacv is a one way type of motor and is forced closed via spring or something then the two wires are just power and ground. it may just be duty cycled by the ecu.

as for coolant lines, im sure with the combination of coolant lines and that one hard line attached to the fresh air inlet for the valve cover would work as an adapter or part of the bypass.

what you can also do is hide the USDM iacv and mount it under the intake manifold or on the firewall and extend the wires and connector to it so it will make the CEL go away.

[Sarthos]

I took the throttlebody off and filled the holes with black RTV sealant. Then I capped both ends with JB weld. That fixed the vacuum thing. Can someone put a DMM to a stock IACV to check it's resistance so I can try to bypass it and disable the CEL? Thanks for the help so far

[wed3k]

just looked in the bible and good spec is 8-15 ohms.

[Sarthos]

As soon as I hit the gas it started surging again. I checked the vacuum pressure on the right side, where the cruise control plugs in and it read 15 in. H g. At the throttle body where that MAP sensor plugs in it read 5 in. H g. Would that mean a leak in the throttle body gasket?

[wed3k]

could be, i hope when you plugged the holes it didnt interfere with the map sensor plug. have you tried a different hole on the intake manifold? (you will have to lengthen the vac line and im pretty sure you should have a lot higher vac at idle as well than 15.