engine and idle up and down when cold HELP!!

[leviathann]

I tried searching....please show me a thread!

I picked up a beaut....98 red accord v6. Third day driving. This morning I started the car and I noticed that all of a sudden the engine and rpm idle started to rev up and down, up and down. One the car warmed up, it went away.....


No CEL. Help will be appreciated.

 

[BadgerType]

did you have anything else turned on? like heater, radio, other electronics?

 

[f23accord2000]

my moms 2000 v6 accord did the same thing also i went in and cleaned the TB and then seafoam it went away after she also got her egr valve done 4 months before it happend so i know it wasnt the egr valve

 

[SilverStreet]

Mine did this the other day too...I can't remember what all I had on but I assume the heater fan, rear defrost, and my system. It didn't do it this morning though...curious.

 

[CG6Lemon]

my moms 2000 v6 accord did the same thing also i went in and cleaned the TB and then seafoam it went away after she also got her egr valve done 4 months before it happend so i know it wasnt the egr valve

x2

 

[finch13]

It's called an Idle Air Control Valve and a Fast Idle Thermo Valve on the back of the intake mani.

The IACV allows air to bypass the throttle plate when it's closed (idle) to keep the engine running.

The FITV is coolant temperature controlled and open up yet another bypass for cold starts and gives you a nice high idle to warm up the car.

Take em off and clean them with carb cleaner and a brush and your problem should go away.

 

[SilverStreet]

This should be enough info to fix it.

http://www.6thgenaccord.com/forums/showthread.php?t=14485&highlight=IACV

 

[SilverStreet]

its too freakin cold right now to do this but I may give it a try sometime...

 

[nyknick1015]

nope is the radiator... if it revs clearly over 1200rpms and then revs down and does it continuously its the radiator... either bleed the system or add more fluid... mines did it because there was a huge air bubble thats why its revving like that... it revs up on air... revs down on fluid so bleed and add some or flush the system... it wouldnt throw a CEL so you might want to check that soon...

when you are done, check your hoses because you might have a leak somewhere

 

[SilverStreet]

best way to bleed?