Problems with Idle

[stasikjan]

On my civic the idle keeps goin up and down, just goes up and down by it self, i heard it may be a some sensor, anyone have any ideas what it could be. And anyone knows where i could get a diagnostic done on it for real cheap or looked at.

[STIBungy]

Could be vacuum leak or disconnected hose somewhere. What was done prior to this happening?

[95GSRB18C]

yea check the Idle Air Control Valve on the back of the intake manifold. do you have a CEL?

[tegedrex]

To test it, idle the car at normal operating temp. Then pull off the 2 or 3 prong harness in the bottom of the valve. If the engine does not lower in idle or stall, more than likely your valve is f'd.

Also before replacing take the IACV off (should be 2 coolant lines and 2 12mm bolts), get some carb cleaner, spray the screen areas that might have a possible blockage. Then put it back on and check for the problem... Also your looking for a code 14 if you throw a CEL.. Good Luck

[notorious]

To test it, idle the car at normal operating temp. Then pull off the 2 or 3 prong harness in the bottom of the valve. If the engine does not lower in idle or stall, more than likely your valve is f'd.

Also before replacing take the IACV off (should be 2 coolant lines and 2 12mm bolts), get some carb cleaner, spray the screen areas that might have a possible blockage. Then put it back on and check for the problem... Also your looking for a code 14 if you throw a CEL.. Good Luck
def the best 1st step..

[Enthalpy]

Also, make sure you have the coolant full, a good circuit to the coolant temp sensor, and the TPS is giving good readings. All of these things can cause these symptoms.

[saN]

That same thing has happened to me on my civic, but I haven't really bother to look at it.