1986 honda civic erratic idle
I have a 1986 honda civic that won't idle periodically. Never happens when its cold. Sometimes it runs perfect. At all other speeds it runs perfect. No missing, etc. its only the idle. When it does act up the minute I push the clutch in the tach needle falls down to zero and the car stalls. It always starts right up. If I undo the gas cap it will sometimes run okay again for a short time then start again. I did replace the gas cap but it didn't help. Could the pcv valve cause this? I have never found it on this car so that's also my next question. Where is that thing? There is a lot of blow by around the oil cap too. Car has 140,000 on it.