killerkali420

i have a 91 honda accord ex that idles up and down butwhen i take the # 21 vaccume line off it stops. can anyone tell me whats going on with my car

nus_dogg

When does it do it? When it's cold or running hot at nomral temp?

killerkali420

all the time dosent matter on the temp

matrix9_11

tighten the idle air valvle scew up i had two different ones do the same thing and another one was the intake gasket it sounds the same

MC Slide Hammer

apparently, idle surging happens with any vacuum leak.

i once had to unbolt my egr valve and had to leave it on loose; i started and ran the car - it was surging.

it just so happens that the fast idle thermal valve tends to be the most common (naturally occurring, when cold) source of a leak on hondas, though that may not be the case here.

try to find out what the source of your vacuum leak is -what is vacumm line 21 hooked up to?- and fix it.