location of idle adusting screw and idel specificaition - 98 honda civic 1.5 L

I can seem to locate the idle adjusting screw on a 2 door honda civic coupe,
98 with a 1.5 L engine. can someone help me? also do you know the idle
specification? mahalo.

 

before we tell you, what reason do you have to adjust it? the idle is
automatically controlled by the car's engine management computer, so if
you have a problem, it's generally /not/ a simple matter of adjusting
the idle screw. describe your symptoms and the car's history.

 

Ditto.

 

yup. playing with it is only going to mask the real problem and make it
that much harder to diagnose.

 

My brother's civic engine service light came on. extraction of the code
revealed that the primary O2 sensor on the catalytic converter was a
problem. we changed it but now the idel is a little rough then before. the
service light no longer comes on.

i check the timing and its okay. the idle seemed on the low side. but we
do not know what it should be. i have a tech. but even if i find its low,
how can i adjust the idle? where is the idle screw?

 

its been almost 2 years, but when i got the code on my 98 civic, i think
it said primary O2 sensor heater circuit malfunction, or something like
that. the engine was running rough and stalling at stop signs, 2 things
it had NEVER done before.

the helm manual told me the primary was the one in the exhaust manifold,
and gave me the spec for the black heater wires. the ohmmeter read 0,
meaning it was a broken/open circuit.

doublechecked on the secondary/bottom O2 sensor on the catalyst. got a
reading within spec. doublechecked the top one. still nothing.

so i replaced the one screwed into the manifold, and everythings been
great since. dealer price was about $220 for it. kragen and autozone
were both out of stock on aftermarket ones, and i forgot to try NAPA.
didnt want to wait to order one online from majestic, but i DID want OEM.

i sure hope you replaced the right one.

 

The primary is ALWAYS the one BEFORE the last cat.

The secondary is the one AFTER the last cat.

I say "last cat" because some cars have a pre-cat upstream of the regular
one.

 

no one has told me where is the idle screw on the 98 civic and how is the
specified idle speed. can someone tell me..aloha.

 

i think were kinda hinting that you MAY have replaced the WRONG O2
sensor. replacing the CORRECT one (primary, in the manifold) would solve
the problem and avoid the "ethnic engineering" youre proposing.

 

dude, for the last time, idle speed adjuster screw is NOT your
problem!!! fix the cause. buy the helm manual if you don't want to
hear what we have to say.

 

Is the new O2 sensor aftermarket or OEM? Some aftermarket O2 sensors do
not work well with Hondas.

Also, have the spark plugs, distributor cap and rotor ever been changed?

As others have said, adjusting an idle screw is not the solution.

 

What's your current idle speed?

 

idle because the PRIMARY O2 sensor is bad

 

its the bosh brand i believed. we don't have reliable tech meter right now
though so i can't tell u.

 

well okay if everyone is speculating the 02 sensor then my brother is at
fault on trying to save money by getting an aftermarket version. we changed
the sparkplugs, cleaned the contacts on the distributor cap and rotor and
check the sparkplug wires for resistance. now its up to my brother if he
want to live with the rough idle. there is no return on the aftermarket
bosh 02 sensor unfortunatley.

 

Assuming you replaced the upstream ( = primary) oxygen sensor (as the code
indicated), I would not expect the roughness to necessarily be the fault of
the (aftermarket) Bosch oxygen sensor. It could be, but I'd do more
checking, first.

Can you describe a little more exactly what you mean by "rough"?

After the car is warmed up, what is the idle RPM?

When it's cold and in the process of warming up, what is its RPM?

When cruising at steady speed, does the engine sound odd?

How old are the ignition wires (miles and years), anyway? A resistance check
is not enough. Are they OEM wires?

Has the ignition timing been checked recently? Fuel filter and air filter?
What is the coolant level, and has the coolant system been serviced
recently? What brand plugs are you using? The distributor cap is due for a
full replacement every few years. Distributor rotors last longer but those
are also due every so often. Cleaning would not be enough for me.

Try the ignition wire check Tegger describes at
http://www.tegger.com/hondafaq/startproblems.html , where you let the car
idle and spray with water the ignition wires. Check other items he discusses
at this site.

These are all basic tune-up items that are due within a few years, anyway.
Spend the money on them so you can eliminate them as the problem.

 

there are 2 sensors. one is down below, in the cat, near the
bottom/front of car near the radiator. this is the one you replaced.
even though its aftermarket, this likely isnt the problem.

you need to replace the oxygen sensor that is screwed into the exhaust
manifold. open the hood, and itll be staring you in the face.

if you feel like going aftermarket, go ahead. if theres a nippondenso
(ND) aftermarket one, that would be best. might have to cut the wires
off the old one, and use the connector. make sure you solder and
shrinktube the connections.

dealer price for an exact fit new one is about $215.

THEN your idle problem should go away. and if you live in a smog state,
you should pass with flying colors next time, if thats any consolation.

if it dies at idle, shakes, runs poorly, it is likely the O2 sensor in
the manifold isnt giving correct readings to the ECU.

the one you replaced below the cat just lets the ECU know if the
catalyst is doing its job. the one up top does most of the work.

 

he said "primary" but he also said "under the catalytic converter", so
im betting they replaced the wrong one. the term primary is also
synonymous with "top" and "front",

ie: primary/top/front/upstream sensor is the one screwed into the
manifold. different aftermarket parts books use different terms.

 

we did change the one on the exhaust manifold. i thought i had placed a
picture to one of my postings..

 

1) It's possible the BOSCH sensor you installed has the wrong
characteristics for your car.

2) If you don't know your current idle speed, it is absolute foolishness to
go noodling with the idle speed screw.

3) The other posters here are showing considerably better judgement in this
matter than you.