I have a 2001 Honda Civic, with approx. 77k miles, that recently has started idling very low. It doesn't happen all of the time, but often, when I'm coming to a stop, the car shakes violently and I can see that the idle is very low. This has been occuring for the past 2 months. When it first started I took it to a mechanic to have a tune up, transmission fluid & oil change...he also replaced all of the spark plugs. He told me that there were no trouble codes coming from the car and that it wasn't a serious problem. He gave me a fuel additive to add to my gas to see if it would help with the shaking. It seemed to help for a week or two, but then the shaking started up again. Last Friday, and again this past Monday, the car has idled so low that it has caused it to stall. The first time I was going up a hill and as I started to release the break and press the gas, it just stopped and all of the lights on the dash came on. I put the car in park and tried starting it back up...it started without any hesitation and no lights were on. The second time it stalled, I was coming to a stop and the idle just went down to 0 and the car stalled...again all of the lights came on and when I restarted it, there was no problem. Does anyone have any ideas as to what this problem might be? I haven't taken it to Honda yet because I don't want to pay and arm & a leg just for them to tell me that it's not a serious problem, or that they don't know what is causing it. Any suggestions would be greatly appreciated. Thanks for your time.

Here_To_Help- Jon

It doesnt sound serious- but it is something you want to get fixed. Could be a setting or a vacuum hose lose. Suggest you dont go to Honda but instead go to Kwik Kar or another place that does oil changes, state inspections etc. My guess is they can diagnose/fix quickly and cheaper than honda

TxGreaseMonkey

1. Start the engine and warm it up to normal operating temperature.
2. Connect a tachometer, normally to the BLU wire coming from the distributor. It is often buried in the cluster of wires near the master cylinder reservoir. Can be difficult to single out, because Honda does a great job of hiding it. I eventually found mine.
3. Disconnect the 2P connector from the Idle Air Control (IAC) valve.
4. Start the engine with the accelerator pedal slightly depressed. Stabilize the rpm at 1000, then slowly release the pedal until the engine idles.
5. Check idling in no-load conditions: headlights, air conditioning, etc. not operating.
6. Adjust idle speed to spec. (normally 450 rpm). The idle adjustment screw is "leaded in," to prevent owners from adjusting them. You will find it on the top end of the throttle body. Take a small screwdriver and remove the lead seal and make your adjustment.
7. Reattach the 2P connector to the IAC valve and everything should be fine.
8. Disconnect negative battery terminal or pull fuse to reset ECM.

2002HondaCivic

Hey I just wanted to ask you if you figured out the problem to your car. My 2002 Honda civic LX pretty much does the same thing. It has not yet stalled on me, but it does shake on idle or when starting the engine. Please let me know.

TxGreaseMonkey

2002HondaCivic, here's what I would first do:

. Check for any codes.
. Ensure correct spark plugs (NGK only) are installed and that they are in good shape. I change platinum plugs every 50,000 miles.
. Change fuel filter, if it hasn't been changed in 60,000 miles.
. Check throttle cable--ensure it hasn't come loose from any brackets and is properly adjusted.
. Warm up engine and check idle rpm.
. Check EGR Valve.

FixHondas

Your problem could be a number of things. Most likely, your RACV (rotary air control valve) is sticking. A quick way to check it is when the idle is abnormally low, you can take a long screwdriver pressed up against it and tap it lightly with a hammer. This will allow the valve to open and allow the idle to return to normal. The RACV is located on th throttle body. It has two coolant hoses that run to it.

Does the problem occur only when the A/C has been on?
What services were performed at the "tune up".
What parts were replaced and what brand was used?

2002HondaCivic

Actually, I haven't got it tuned up yet. It doesn't just happen only when the A/C is on. Unfortunately, i am not too good with engines and car parts so i don't think i'll be able to do exactly what u tell me. The car has apprx. 47,000 miles on it. The car sometimes shakes and sometimes doesn't when at a stop light for example. Most of the times, if i floor it the whole first gear and stop slowly at a light, for example, it won't shake. It's pretty weird.

FixHondas

The RACV is notorious for carbon buildup causing it to stick. It is just a valve that rotates to allow air into the intake manifold to control idle speed. It will tend to stick more when the ECU gives it small adjustment commands (regular driving). When adjustment commands are larger the RACV moves with enough force to free its valve (Wide open throttle driving). This is still the first place I would look for diagnosis.

2002HondaCivic

Thanks for that! I will let the mechanic know to check that. The problem occured mainly after my sister drove the car. One day she was driving while it was raining and turned pretty quick. Next thing, car went out of control and went into the curb. No body damage was done. The left and right arms had to be changed though along with the tire and rim. I was thinking maybe the transmission mounts or engine mounts ? Maybe that is why it is shaking? Just taking a guess. Please let me know! Thanks

FixHondas

2002HondaCivic- The RACV information was intended for Jenni536. (I didn't realize this was a multi member thread)

You could have damaged mounts from the impact, which would cause engine vibration to transfer to the body. I have also seen cracked transmission cases from harsh impacts.