Rough idle on 1986 honda civic 1.5 carb

SOURCE: 1989 honda prelude enigne idles high then low irratic

I had the same problem on a Rover. There was a leak in inlet manifold that was caussing the problem.
To verify, spray some sealant to temporarily seal the inlet manifold .and the eratic idling should disappear for some time.
If it does, you know there is leak in inlet manifold which you can take of and refit with a new gasket.

SOURCE: rough idle stalls at low rpm's

hello first check your idle with the car running foot on brake see were your rpm reading is if your below 500rpm check your label underhood for your curb idle setting second see if theres a adjustment screw you can increase were your gas cable lever rest against your set screw underhood if you feel confident enough remove your iac motor idle air control valve if the bore were the end of the pintle extracts out to close has varnish builup our carbon it will stick creating vacuum leak type senario causing stalling rough idle sometimes even no start conditions good luck

SOURCE: 91 honda civic dx. Starts, runs for a few seconds then stalls

Try pounding on the gas tank with a rubber mallet or similar tool. (careful not to dent the tank) Try starting it. If it runs, replace the fuel pump (it's nfg). I've diagnosed numerous fuel pumps this way. Remember the pump needs to be replaced, if you drive it, you don't know when it'll fail for good. Hope this helps. Please post the results.

SOURCE: 1995 honda civic idle problem

iac valve or tps

SOURCE: 1994 honda civic 1.5 16v stalling after pressing accelerator from idle

Another place to look is your IAC, or Idle air control valve. It is bolted to the back of the intake manifold, and can be removed and cleaned. It is usually the cause of most Honda Idle problems.