Simptoms:
When the weather is hot (25 to 30 Celsius) and the acceleration pedal is not being touched, engine raises rpm even to 2000 rpm and keeps it that high. Eventhought I do not touch the acceleration pedal and engine is at its working temperature. When I lift the acceleration pedal (I lift it up, I do not press it) then rpm falls down to 600-700 and engine begins to shake and jump (allthough thease are pretty low rp so it is not weird)

Car is Honda Civic EG4 with manualnim shifting, engine is D15B2 and nothing has been modified

What could be causing it? How do I fix it?.

 

Nobody knows ?!
Please help

 

Sounds like your throttle body could use a good cleaning - have you tried this yet?

 

I'm sory but my tech English is not so good. Can you explain what it is? With photo maybe
Tnx and sory again

 

ur accelaration pedal shouldnt not be able to be lifted at all in its
normal position. It looks like something is causing ur pedal to slightly
be pressed in permanently, it could be from scrweing around with
the cruise control too much or something else.
Your throttle is pressed in probably a good half inch. thats why you are able
to lift it.

 

I don't have cruise control. I'm gonna try to clean the wire that goes from pedal to engine. Maybe that's the problem. Tnx for help, tnx big time
Nevertheless, what is a trottle body?

 

your butterfly valve is probably sticking. take off your intake and look at the valve to make sure its fully closed. you may simply have to adjust the throttle cable. take a look.

 

Are you sure? because this is happening only when is hot outside. when is normal temperature outside it's running normaly