92 Accord Idle Speed Question

Does anyone know if the idle speed is adjustable or if it's controlled
by the computer?

I'm getting some fluctuation that I need to get fixed.

Thanks

 

It is adjustable AND controlled by the computer. There is an idle
control screw somewhere on the throttle body.

If you have fluctuating idle, you most likely have a vacuum leak
somewhere, so try to find this before you adjust anything. Fill up a
squirt bottle with water (others recommend using carb cleaner) and spray
a fine mist around the various parts of the intake system. When you get
a drop in idle speed, you have found the leak.

If this does not work, start pinching the various vacuum hoses until you
see a drop in RPM. If you do find a hose that allows you to drop the
RPM, follow it to look for leaks or faulty valves etc.

Another thread dealt with the same issue on a CRX. The original poster
in that thread found that his fast idle valve was leaking. It is a
thermo-wax valve that allows extra air in while the coolant is cold. His
was leaking air all the time.

If you do need to adjust anything, first get a shop manual as the
process is not completely straight forward. The best manual is the one
from http://www.helminc.com, but if this is the only work you are going
to do on the car the Haynes manual would probably suffice.

There is a stop screw on the throttle body (close to where the gas wire
is) that looks like the idle speed adjustment on carburetors. Do not
touch this screw, as it is factory set and is not used to regulate the
idle.

 

Thanks for the info. I'll try what you suggest below.

To be more specific, here is a little more detail on what is happening.
When the choke is on everything is fine. When the car has warmed up the
idle drops to 700 rpm and the car is idling rough. After a minute or so
something happens and the idle increases to 750 or 800 and the engine
runs very smooth. I'll start driving again and have to stop at another
light and the same thing happens again. In fact i was getting off the
freeway yesterday and the same thing happened when I got to the bottom
of the off ramp. The idle did correct itself a little more quickly this
time though. The car vibrates more than usual when in reverse which I
believe is because the front engine mount needs replaced.

Other than this the car runs great for 139k miles.

Thanks

 

Thanks for the scan. I'll download it and take a look at it.

Jeff

 

Was ther dist. housing replaced per Honda's extended warrenty? Is
there evidence of rusty junk under the dist cap? (dist bearing going
bad) Do the spark plugs have over 50,000 miles on them? bob

 

The distributor was replace a while back but I had to pay for it. I
wonder if they owe me money for that work.

The plugs are replace every 30k. I take the car in for all scheduled
maintenance.

Jeff

 

I have had this same thing happen to my car. (92 accord LX 5 sp.) It
seemed to go away on its own after a few days. C.P.U. hiccup? Bad Gas?
I don't know for sure. bob

 

The battery went out on me, it was 6 years old so I thought maybe that
was causing it. I replaced it a month ago but I'm still having the
problem.

Jeff

 

Might take a look in the air intake stuff. There are some passages and
linkages between the air filter intake and the injectors that may be
gummy or dirty.
Also, my mechanic drilled out the four plugs on the top of the E.G.R.
system and cleaned out the passages. He taped the holes and put short
bolts back in. Took him about half an hour. Might make a difference.
bob