96 EX Revving and Not Constant

[darkghost220]

Hey Everybody,

I recently bought a 96 Civic EX with 125K miles on it. The previous owner took car of the car and everything checked out when I took it for a test drive and decided to buy it. I know that at this point in time I will need to replace some wear and tear items and all and I do understand that the car is not perfectly sound. Everything works great, however I had one minor problem that I wanted to see if I could fix or understand what is wrong. When i am stopped at a light, and the car is in neutral, sometimes the engine will rev and then de-rev I guess you could say. The rpms do not stay constant. This only happens maybe a couple times out of my day when using the car during the whole day. What could be the problem?

 

[RonJ]

Bleed the cooling system and clean the IACV.

Any CEL codes?

 

[darkghost220]

CEL codes? sorry you are talking to a complete noob. could you break that down for me?

 

[RonJ]

Click on the codes and IACV links in my signature.

 

[b16c]

try cleaning the throttle body too.....it may helps.

 

[darkghost220]

thanks a lot i'll get back to you on that in a couple days

 

[Trekk]

CEL = Check Engine Light
MIL = Malfunction Indicator Light
Just to clear thing up for you.

My guess would be the IACV as its a highly common problem.

 

[SpeedTechnik]

Since you aren't in California, you can go to a local Autozone and they can check your cell codes free of charge. Post the results here. Clean your iacv, your throttle body, and check the air filter (just to make sure there is a good amount of flow). Also, are there any weird sounds? (such as hissing? There is a possibility there can be a vacuum leak)

Here are some good informative videos by ETCG to get you started:

For bad idle:

http://www.youtube.com/watch?v=L788jKEVblY

Here is one on a Vacuum Leak:

http://www.youtube.com/watch?v=9CPqbaSgcok

Here is another on bleeding the cooling system:

http://www.youtube.com/watch?v=zUpXgAJ1gjU

 

[darkghost220]

thanks a lot guys. I truly appreciate it. As soon as I get it done, I'll you guys know for some closure. Thanks again!

 

[darkghost220]

Hey everyone, it turns out to be a couple things wrong. first the support plate holding my gas pedal is pretty loose and flimsy, so that was one of the problems due to over revving, and as you guys said my intake filter and throttle body needed cleaning/ replacement. I mean this car does have 126K miles so it was time