Rpm's idle high when engine is hot.
 

Just like the title says. The car starts fine each morning before I go to work. I recently bought a 1998 Honda civic ex coupe. It has over 180k and I had a tune up done to it. The car drove fine until recently the rpms go way high, at times it goes over 3k rpms when I park. I've noticed when I drive the car to the store locally and park the car, and turn it off, I can't start it up right away. I have to wait till it cools off in order for me to start it up again. Abe suggestions will be appreciated

Re: Rpm's idle high when engine is hot.
 

Got codes?
Got a way to read live engine data from the computer?

Is the radiator low? Fill it up.

Re: Rpm's idle high when engine is hot.
 

The radiator level is good. How can I check the codes?

Re: Rpm's idle high when engine is hot.
 

Code reader or a Scanner. The cheapest of cheap only reads codes. A good one can give you FF and live engine operating data.

Re: Rpm's idle high when engine is hot.
 

Ok but I don't have a code reader or scanner. Can autozone or a car part store read me the codes?

Re: Rpm's idle high when engine is hot.
 

Usually. Call and ask.

If they find no fault codes, that doesn't automatically mean there is no problem. There can easily be problems that don't set codes.


Right now I'm suspecting a misreporting ECT sensor. This could probably be read in a live data list during a no-start event.

Re: Rpm's idle high when engine is hot.
 

Is there a way I can find out by connecting something and the computer flashes a series of lights?

Re: Rpm's idle high when engine is hot.
 

You can try the SCS jumper method to see if it will flash codes in a 2 digit format, that at least would tell you if there are any codes stored.

Re: Rpm's idle high when engine is hot.
 

I got a code reader off Amazon for $12 works with my phone. Also check for carbon build up in the intake. Could be iacv. YouTube videos are very helpful

Re: Rpm's idle high when engine is hot.
 

Got any fault codes?
Will this thing read live data from the PCM?