Hello,
I am away from home and need to fix the car to go back (500 miles)
It is a 2004 Civic ES8, D15Y3 engine, 72000 miles.

The car started having high idle (1400 rpm) and no CEL. This happened after having driven a whole day non stop.

I tried today to adjust the little screw that stops the throttle valve when released, and it idle started searching between 1200 and 1600 rpm. No CEL reported. I even loosened that screw to allow the pulley to be completely released and it showed the same thing. I also disconnected battery and tried to do an idle relearn, but when the throttle is released it keeps searching. IACV is clean.

I need a quick fix to drive back home. Quick help needed please.

Thanks in advance and I'll also keep searching on the forum for similar issues, but so far did not find any topic describing idle problem without CEL reported.

thank you.

 

Just for information, i had similar issue few months ago, sometimes high idle (1800 rpm) and sometimes searching idle. I fixed that by adjusting the throttle puley screw.

Today, that's not working.

I have not changed any part yet.

 

You shouldn't mess with that screw, that is not an idle adjustment. The idle is controlled by the ECU.

You might need a new IACV, or you could possibly have a vacuum leak. Check the PCV valve, PCV hose, EVAP canister purge valve, intake manifold, throttle body, brake booster hose.



If you're able to drive the car, do it, and then check things out after you return home.

 

Thank you
The car drives fine and it is only anoying when I come to a stop hearing the enging going high and low. Also, when running slowly on 1st or 2nd in the range where it searches. Apart from that it is fine.

 

I've spent last couple of days searching for topics related to searching idle, hunting idle, idle problems in general. A number of them describe the same problem as I have, and the common suggestions are vacum leaks and IACV check. The odd thing is that none comes back to say if he has been able to resolve the problem ......

 

Check the coolant level in the radiator.

 

OK, I was discussing this situation with a friend today and I think there is another path not to ignore.

I remembered when I was driving from home to here, i started with full tank unleaded gasoline. No problem. After about 400 kms I had to refuel. There was no unleaded gasolin at that service station and I added about 1/3 of tank of what's called "Super Gasoline" which is leaded. After few hundred km's driving, I started getting this idle issue. So, according to a friend, the O2 sensor or something else got poisened by lead and that's where it is coming from.

I also remember the first time I ever had an idle issue i put a mixture (unleaded/leaded) in the tank.

What do you think guys? Should I first inspect this path and run the car until it is empty then refuel unleaded, or check for vacum leak first?

Thanks for the help in advance.