fitv or the eacv

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rkwoos12

New Member
hey guys im still haveing a problem when i start the car when cold it will idle a little high like 1500 sometimes 2000 rpm then it will go down when warm but after i drive it and i stop the idle starts to go up and down, i took the fast idle thermo valve off and took it apart and cleaned it and it help for a little bit
i tested it by the manual and im geting little sucktion on lower port the manual says there should be no sucktion at all on lower port when warm could it still be my fast idle thermo valve causeing this problem or would it be the electronic air control valve? let me know what you guys think
 

MthaFuknGreen

Green on the scene.
A quick test to see if your FIV is bad follows Take a cereal box, or anything made of the same kind of cardboard. Cut a piece of the cardboard to fit between the FIV and the intake manifold. Place the cardboard piece between the FIV and the intake manifold and bolt the FIV back on. Let the engine heat up. if the bouncing goes away, then you know it's the FIV. If the bouncing is still there, then it's something else.
 

MthaFuknGreen

Green on the scene.
I suppose, but it's more effective with the cardboard.
Not to mention easier.
 

welfare

Ancient Member
easiest way is:
take off intake tube so you can access the throttle body
start the car, let it start acting up
there are 2 holes, one above the other, use your finger to plug them one at a time and see if car smoothes out.
upper hole is IAC (back of inteke manifold)
lower hole is FITV (under throttle body)
replace or bypass faulty unit.
 
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welfare

Ancient Member
Also sometimes an air intake leak can cause the same problem, check for leaks and probably replace your pcv valve while you're in there, they don't last forever
 

rkwoos12

New Member
it has new pvc valve installed when i installed the motor last month. and right now i dont have a air intake tube
just filter on intake lol
but i still think its the fast idle valve because it is still sucking air when the car is at normal operating tempature manual says if it is sucking any air after car has warm up that it is leaking and needs replaced. and i cant find one of these no where.


Also sometimes an air intake leak can cause the same problem, check for leaks and probably replace your pcv valve while you're in there, they don't last forever
 

welfare

Ancient Member
You didn't say what model or engine you had, it doesn't really matter anyway, unless you regularly see cold weather (30 degrees or lower) I would jsut do as stated above and bypass it, I actually used a piece of 3 layer metal gasket material that I cut from an old dumptruck headgasket, but you can really just use a thin piece of aluminum or other type of gasket material. then either leave the coolant hoses attached or bypass as well.
Another way around this is to get a throttle body from a junkyard that doesn't have the valve on it (there were some models that only used the IAC motor).
Your car may have a lower than normal idle at startup in cold weather, but it should still run fine, if not then reset the ecu so it can relearn where the IAC needs to be to keep it running.
 

rkwoos12

New Member
thanks man it is the fast idle valve, and the modle is d16z6 vtec engine in 94 honda civic ex, im buying me another fast idle valve to put on it so we will see how that gose, thanks for you help.


You didn't say what model or engine you had, it doesn't really matter anyway, unless you regularly see cold weather (30 degrees or lower) I would jsut do as stated above and bypass it, I actually used a piece of 3 layer metal gasket material that I cut from an old dumptruck headgasket, but you can really just use a thin piece of aluminum or other type of gasket material. then either leave the coolant hoses attached or bypass as well.
Another way around this is to get a throttle body from a junkyard that doesn't have the valve on it (there were some models that only used the IAC motor).
Your car may have a lower than normal idle at startup in cold weather, but it should still run fine, if not then reset the ecu so it can relearn where the IAC needs to be to keep it running.
 

rkwoos12

New Member
thanks man it is the fast idle valve, and the modle is d16z6 vtec engine in 94 honda civic ex, im buying me another fast idle valve to put on it so we will see how that gose, thanks for you help.

at the moment is has been staying below 30 lol.
 
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