idling problem pls help.

i got a 93 1.6 vtec del sol, sometimes it idles around 1000 and sometimes it idles around 500 and it when it does its really rough any help on what the problem is...any help would be good thanx...

Might be the O2 sensor. I'd start with the basics though - spark plugs, wires, air filter, fuel filter, and a can of fuel injector cleaner.

plug,plug wire and filter is all brand new...how can it be the o2 sensor i was thinking more along the lines of TPS or IAC not o2.thanx.

its your iac valve. All honda's have problems with them. If you ever run low on coolant your iac will overheat and malfunction. Get a new one, intstall it, bleed your cooling system and then let your car idle with no loads for ten minutes.

its your iac valve. All honda's have problems with them. If you ever run low on coolant your iac will overheat and malfunction. Get a new one, intstall it, bleed your cooling system and then let your car idle with no loads for ten minutes.

Hm... I'll have to give that a shot myself. I'm actually experiencing the same issue (usually idles around 700+/- rpm's, but sometimes around 300-500 rpm's though it's not idling rough) and have been slowly chasing down the cause. Been too broke to try the basics though, let alone a new IAC. How much does having a new IAC installed usually run anyway?

I've never run low on coolant before though, but the car's 10 years old so maybe it's just due for a new one. :dunno:


speedster_74:
If the O2 sensor is going or is bad, it can cause your idle to jump around as well. My plugs and wires are also in good shape and I had just recently cleaned my air filter and replaced the PCV valve. That left either an exhaust leak, engine ground wires, fuel filter, fuel injectors, or a sensor somewhere. Since we seem to have the same issue and same motor, I'm interested to see if replacing the IAC corrects the issue if you end up doing that. Let us know how it goes.

well, the iac valve is about $130 and you can install it your self in about 10 to 15 minutes. Its located on the back of the intake manifold to the right of the TB. It has one connector that plugs into the bottom. I can get the exact install and idle adjustment after install instructions if needed. mine idled just like that for about a year too. I finally replaced the IAC valve and no more probs. There are actually service bulletins on it for other hondas. But like i said the is specific instructions to get it to idle right after the install, or else it will do the same as it was before.

I'd be interested in seeing those instructions if you can get your hands on them. I'm leaving for about three weeks today though so it'll be a while before I'm around to read it. Feel free to PM it to me if you want. If not, I'll see what I can do when I get back. Thanks. :)