rick10

So lately I been noticing that my car idles at very low rpm. It does not happen all the time , it actually happens here and there.

When I start my car it usually stays at around somewhere between 600 and 700 rpm. However at times when I stop at a red light the rpm goes down to 300 or 400 and then slowly goes back up to 600 and 700.

Also i ve notice that when I stop somewhere the car again goes down below 500 and i can feel a little shaking , not too noticeble but enough for me to feel it , about 2 seconds.

I dont have a problem starting that car and the car have never shut off on me. Furthermore acceleration seems fine and i dont feel any loss of power.

This does not happen all the time but lately its been hapenning more often than before.

Also if i m travelling at speeds over 60 and put my car in neutral again the rpm gauge goes below 500 , somewhere around 300 rpm

Tomorrow I m going to change the fuel filter as i have never changed it before and i highly doubt the previous owners had. I m not sure if the main relay could be doing that but I guess i can take a look at the soldering (thnks robb for the diy) ..

Opinions ????? thanks

MPR

My car does a the same thing time to time.


Did a little research and there are several things it could be: IAC valve, tps sensor...the list goes on.

Some good info here:

Fixing an erratic Idle

rick10

great info ! thanks

I will check that today

winner007

What kind of civic is it? What year is the car? It is 100% not your main relay. When was the last time u had a tune up? What is the mileage of the car. So the car is not misfiring? Check the IAC. when it is cold does it rev up and down? Also clean the throttle body. Check the TPS sensor. Do a compression test and make sure all cylinders are good. I don't think u have a bad fuel filter.

rick10

After doing some research i m going to clean the IAC valve , which seems pretty easy . A lot of people have done it and it seems to have ix the idle problem in their car.

My car is a 2000 civic , 230 000 kms , tune up was done 4 months ago so i can not be that. However the distributor cap was not change so I m going to check that too , as it may be dirty.

Next step will be check for vacuum leaks although I m a little confuse on what to use to check for leaks .

I will update , hopefully later today ( if i dont mess up my car even more)

MPR

Yeah, mine's a 2000 as well, SiR model (b16). 238,000kms.

Everything tune-up related has been changed in the last 2 years except original ignition wires and coil...lol (and original clutch). Still purs like kitten and pulls like a tiger!

rick10

Ok after doing an extensive research I finally narrow down the problem. I believe the IAC valve needs to be clean. I found a DIY thread on how to do it in my engine ( d16y7) however as it turns out to remove the IAC valve you need to remove the intake ( pretty easy), strut bar ( i didnt have to remove it) and the TB which is where I got stock , the 4 screws would not come out , not matter how hard i ve tried they are stock there , those damn screws wouldnt move so i just gave up and put everything back in. The IAC valve is hold by 4 screws , 2 on top are pretty easy to remove but the bottom ones are a pain in the bud , reason why all the above have to be removed.

However I did removed my distributor cap and cleaned up with some contact cleaner ( it was somewhat dirty) , I also spary some of the sensors with contact cleaner.

I drove the car for about 30 minutes and the rpm only drop once ( in the first minute) below 500 , after that its being running normal ( above 600 rpm) so i m not sure if i fixed the problem by cleaning the distributor cap.

I also went to my mechanic and i was told the samething IAC Valve needs cleaning , quote is 40 bucks to do it , so i may actually just take it in next week ( if the problem comes back) and have him cleaning the valve for me.

It is a pretty common problem with civics specially high mileage civics , found so much info about this topic

Robb

iTrader: (1)

Have these checked:

check battery and alternator voltage !
check ignition timing
check compression