My 1999 honda accord (4cyl) is idling rough. It smooths out once accelerating. any ideas?

also, sometime when driving down the highway, it will instantly die. It always starts right back up though.

It has been doing this for a while, but just today started idling rough.

I would greatly appreciate any input.

 

Give more info on the car. 5 spd or auto? How many miles?
Does it have rough idle in neutral as well, or just in drive?

 

Give more info on the car. 5 spd or auto? How many miles?
Does it have rough idle in neutral as well, or just in drive? When was the last oil change? My first thought would be to make sure that the air filter is clean.

 

Idle Air Control Valve. Aka IAC valve. Its mounted on your intake manifold with two 8mm bolts. You dont have to buy a new one, which any store or dealer would suggest. Remove it and clean out all the "gunk and junk" with Carb cleaner, you'll be amazed how much crap will come out. Then use Brake clean to clean the Carb cleaner. It'll be just like new. Btw, be carefull with the gasket, dont rip or bend it.
Takes 15 min bro. Good luck.

 

could you give more info like the location of the iac valve please? is it right by the throttle body?

 

its your ignition switch. this happened to my 99 accord too. there was a recall for this a while back. go take it to the dealer and they'll fix it for free

 

yea you can adjust it from your throttle body i believe it just requires a screw driver

 

Here's a quick tutorial on how to fix your idle problem if it's related to your IACV, i just did mines today, tookit off and cleaned it out really good and now my idle is great. almost perfect i can say. https://honda-tech.com/zero...age=1

GOODLUCK! 3 dollars for a bottle of carb cleaner at kragens will do the job. =] :thumbsup: