Engine Performance problem
1995 Honda Civic 4 cyl Front Wheel Drive Automatic 145000 miles
Hi, I have a 95 civic LX, and there is a problem with the idle. When I start the car up, it goes from ~1200 and works its way up slowly to ~15/1600 RPMs. Drops down normally when I shift it in gear. The problem seems to be that the longer the car runs, the more the idles drop down in general. After 5 minutes, i'm idling in park at 700, in gear at 4/500. Another 5/10 minutes, and it stalls when I pull it into the parking spot. I replaced the PCV valve and hose, which were clogged (but not clogged now).
Sounds like the Idle Air Control is sticking. You can try removing it and cleaning it out with carb cleaner to see if it will fix it, or at least make a difference to let you know we are on the right track.It should look like this
April, 17, 2010 AT 10:16 AM
I took the IACV out, sprayed it with brake / carb cleaner, shook it a bit, let it dry out, reinstalled it, and the problem persists. The car acts normally (aside from shifting a little high, around 2500/3000RPM), but as soon as I take my foot off the gas, when it drops down to idle, it drops down more and more every time.
April, 17, 2010 AT 10:22 AM
If it helps, the car was sitting for a year or two in a driveway. Had a nice moldy smell and a rat (or squirrel) nest in the back speaker, as well as underneath the under-hood fuse box. I took the head off, and had an apprentice mechanic put it back on to replace a head gasket. It went into a garage where the Coolant sensor was fixed, along with the tie rod end.
Figured I would provide a little information.
April, 17, 2010 AT 12:27 PM
If the ignition timing, cam/crank timing are correrct, the IAC is what controls the idle. They can stick and not set any code, especially if the vehicle sat for a long time. Just for laughs, try tapping it gently while the car is running to see if it makes a change, I have had them move when tapped before, but just die down like you describe
April, 17, 2010 AT 6:18 PM
So assuming that there are no vacuum leaks, and the IAC valve is working properly, what would you recommend next?
April, 18, 2010 AT 3:28 PM
Clean out the throttle bore around the butterfly to be sure the correct amount of air is getting in. Use carb cleaner and a rag