my boy wanted me to post this up for him. "my 97 civic ex has problems idling when the motor is cold. If I dont put pressure on the gas when starting the car it will cut right off. And when I am driving it and I come to a stoplight(motor is still cold)it will cut off. Also when it is cold there is a slight knock at the 2000 rpm range(give or take a couple of hundred?) The timing is correct and the car runs fine after it is warmed up. I am thinking it is vacuum? help me out please? this $hit is really bothering me". yea...so any advice would be appreciated. thankz guys.

 

its been a long time since ive look d at the owners manual..but is there and automatic choke??..if so, it might be shot..or the heat sensor is out

 

simple, clean TB first.
Might have buildup restricting air into motor at idle.

 

check vacuum lines and Throttle body..

 

any mods on this car we should know about??

 

*thinking*..*dangerous* ..but when was the last time u clean d out the throddle body?.. shoot some Sea Foam in an clean it out..something might be hanging up from the carbon buildup

 

thanks for the advise. i am the dude with the problem. i thought i should jus go ahead and register with this site because its giving me a better understanding of the wonderful cars we drive. i am much more knowledgeable on "tech" side of my ride.

i cleaned out the TB and it is still doing the same thing but only sometimes. The idle is still weak if it does start up without any problems.

 

intake, header, cat-back..... nothin serious

 

To achieve a higher cold idle, air is bypassed around the throttle butterfly. This is done with the idle air control valve (IACV) and the fast idle valve(FIV). Both employ a type of thermo-wax that melts as the engine warms up, restricting air flow down to a warm idle speed.

The IACV is bolted to the intake manifold just after the throttle butterfly and has two small coolant lines on it. The FIV is a little further back and has two philips head screws on it's top plate.

I suggest you check both of these out, looking for clogs, etc.

 

Yea definitely check those.. I had a similar problem and it turned out to be the IACV.

 

thanks for all the replys. im going to check it out.