Hey Guys . I bought a 1992 Honda Civic hatchback Dx . When i first got it the Engine was good , days passed and the rev started going up and down .. At first it used to go away after like 5 mins or so . but now its just there .. Some people tell me its the iacv, and i tried cleaning it, but it still was the same . and some people tell me its the ecu .. dont know wat to do .. plz help !!

 

Do a search for surging or idle problems on here and you will find the most likely answers,there are several threads and severalwrite-ups on how to troubleshoot and fix the problem.

 

are you overheating? might be air bubbles in the coolant system. could be time to change your T-stat. Is your fan turning on? do a search on FITV, no cost or replacement part if you are a diy.

 

Try to explain your problem better. You say the rev goes up and down, does that mean that the RPM's bounce up and down at idle? What RPM's does it bounce between? Do you ever hear any misfiring? Does the motor ever stall or almost stall? Try to find out what happens if you try to start moving when stopped on a steep upward hill. Post if trying this causes any misfiring. Check all of your grounds first with a meter set to measure resistance. When testing grounds, touch the meter probes to bare metal on the parts the ground wires connect to, not the wires themselves or the bolts holding them on. Try adjusting your idle screw using the TPS signal voltage reading to see how much the idle has changed with each adjustment. You can note the TPS voltage at closed and wide open throttle while you have the meter hooked up. Check the MAP sensor signal voltage at idle after the motor is completely warmed up to normal operating temperature. Post any other information you have about mods, this problem, and any other engine problems you have seen since buying the car. You can also try testing the spark at each plug wire.