[HELP PLEASE] Very Chunky Idle at Start Up

[Beaz]

Latley my 91 accord has been idling extremely rough right at startup. It clears up after about 5-20 seconds depending on how cold it is outside. Before it smooths out it will be rough under acceleration to. Any ideas?
-Thanks

[MadSpleen85]

Mine used to do that also. Only seems to happen when it is cold out.. I just gave it a little gas and it smoothed out right away. Later

[djcaz_aom]

Check your distributor cap for traces of carbon. Clean the contacts or replace the rotor and cap.

[Beaz]

I though cap and rotor too. But tis only doin it when its cold out... could that still be it?

[djcaz_aom]

Did you replace the rotor and the cap? If yes, then check around the fuel injectors for leaks.
* If good, then it may be a clogging fuel filter.
** Does the battery have good charge? Not enough charge can cause this as well.

[Leung]

i was just about to say have you done a tune up lately?

[OnBBS17s]

I had the same problem. This is what I did. (do at your own risk, not that there is really any risk involved)

open this bad boy right here:

then there should be a little ring with knotches in it, while the car is on and cold, (doing that rev thing) turn that ring until it lowers your RPMs, you should be able to hear it.

[djcaz_aom]

While you are at it check the IAC valve. The green arrow.
1. Use an ohm meter and measure the resistance at the connect in the pic.
**It should read between 8 and 15 ohms.**

2. Check to see if there is continuity(don't know if I said that right), between each wire and ground. (Red terminal to one of the wires in the plug, and Black terminal to ground. Then the next wire. If there is continuity, then replace the IAC valve.

**Basically this valve controls the amount of air allowed to bypass into the intake mani.

As for the RED arrow, this is the Fast Idle Thermo valve.

1. You want to start the engine and allow to idle.
2. Remove the cover as stated in the above post.
3. Make sure there is air flow. If no air flow is present, replace the valve.
4. If you have air flow, allow the engine to warm up to the point when the fans kicks in.
5. Check now for air flow, if air flow is still present, you need a new valve.

Hope this helps.

[lilude]

what about blocking off the thermo valve would that change anything

[CallMeRay]

a rough starting idle can also by caused by the pesky rocker arm o-rings leaking oil onto a plug or two, making for a rough start, does your car smoke at all when you start it?