Honda Car Forum

Good day,

98 civic LX 5 spd with 285000kms.

After being on the highway during my 35km commute, when I pull up at a red
light, my RPMs stay at around 2500. After a few seconds, or if I pump the
gas pedal, the RPMs go down to about 1200-1500.

This just recently started happening. Don't know if its related, my AC
recently stopped cooling. Sounds like the compressor doesn't come on. Is
there anything in the AC mechanism that affects idle speed?

Also, have recently done the following, all with OEM parts from the
dealership:

Spark plugs
Distributor Cap
Distributor Rotor
PCV valve
Air Filter
Front wheel bearing
rebuilt all struts
all new suspension components front and rear
4 wheel alignment

When I did the distributor cap, I actually had to remove the distributor so I
could drill out 2 of the bolts holding the cap on. (They were rusty and
broke). I was expecting the removal of the distributor to be harder, but it
was pretty much idiot proof. It appears that you can only put the
distributor back in the block either the correct way or 180 degrees wrong.
So if you are careful, you should be OK.

Also, since my distributor had never been removed before, it was easy to put
it back exactly the way I had removed it as I could see where the washers for
the adjustment bolts had been before (good old corrosion at work here again).
Checked the timing with a timing light after, and all is well.

Note that the idle fluctuations occured before I did the tune up work (which
was overdue anyway).

I am also fairly certain the car is running pretty rich. Fuel economy is
relatively poor (around 11-13km/liter or 25-30 US MPG or 31-36 UK MPG), and
the exhaust pipe is pretty black. I have run several bottles of injector
cleaner and Lucas Oil Upper Cylinder lubricant over the past few tanks and
seen no real improvement here.

The car has great performance, when you want to step into it, it accelerates
really well. However, I have also measured fuel economy on a light foot, and
the mileage is about the same.

Driving pattern is mostly highway, we live about 20km outside the city.

Any ideas of what I could check would be greatly appreciated.

Thanks
Terry in Winnipeg

--
Message posted via http://www.carkb.com

my suspension parts were aftermarket, not from the dealership... though I
doubt that has any bearing on my idle issue.

t

loewent wrote:
>Good day,
>
>98 civic LX 5 spd with 285000kms.
>
>After being on the highway during my 35km commute, when I pull up at a red
>light, my RPMs stay at around 2500. After a few seconds, or if I pump the
>gas pedal, the RPMs go down to about 1200-1500.
>
>This just recently started happening. Don't know if its related, my AC
>recently stopped cooling. Sounds like the compressor doesn't come on. Is
>there anything in the AC mechanism that affects idle speed?
>
>Also, have recently done the following, all with OEM parts from the
>dealership:
>
>Spark plugs
>Distributor Cap
>Distributor Rotor
>PCV valve
>Air Filter
>Front wheel bearing
>rebuilt all struts
>all new suspension components front and rear
>4 wheel alignment
>
>When I did the distributor cap, I actually had to remove the distributor so I
>could drill out 2 of the bolts holding the cap on. (They were rusty and
>broke). I was expecting the removal of the distributor to be harder, but it
>was pretty much idiot proof. It appears that you can only put the
>distributor back in the block either the correct way or 180 degrees wrong.
>So if you are careful, you should be OK.
>
>Also, since my distributor had never been removed before, it was easy to put
>it back exactly the way I had removed it as I could see where the washers for
>the adjustment bolts had been before (good old corrosion at work here again).
>Checked the timing with a timing light after, and all is well.
>
>Note that the idle fluctuations occured before I did the tune up work (which
>was overdue anyway).
>
>I am also fairly certain the car is running pretty rich. Fuel economy is
>relatively poor (around 11-13km/liter or 25-30 US MPG or 31-36 UK MPG), and
>the exhaust pipe is pretty black. I have run several bottles of injector
>cleaner and Lucas Oil Upper Cylinder lubricant over the past few tanks and
>seen no real improvement here.
>
>The car has great performance, when you want to step into it, it accelerates
>really well. However, I have also measured fuel economy on a light foot, and
>the mileage is about the same.
>
>Driving pattern is mostly highway, we live about 20km outside the city.
>
>Any ideas of what I could check would be greatly appreciated.
>
>Thanks
>Terry in Winnipeg

--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...-cars/200710/1

"loewent via CarKB.com" <u10197@uwe> wrote in news:792417cc18b54@uwe:

> Good day,
>
> 98 civic LX 5 spd with 285000kms.
>
> After being on the highway during my 35km commute, when I pull up at a
> red light, my RPMs stay at around 2500. After a few seconds, or if I
> pump the gas pedal, the RPMs go down to about 1200-1500.

Still too high.
>
> This just recently started happening. Don't know if its related, my
> AC recently stopped cooling. Sounds like the compressor doesn't come
> on. Is there anything in the AC mechanism that affects idle speed?

A switch to tell the ECU to increase the idle.
>
> Also, have recently done the following, all with OEM parts from the
> dealership:
>
> Spark plugs
> Distributor Cap
> Distributor Rotor

No plug wires? They don't last forever.

> PCV valve
> Air Filter
> Front wheel bearing
> rebuilt all struts
> all new suspension components front and rear
> 4 wheel alignment
>
> When I did the distributor cap, I actually had to remove the
> distributor so I could drill out 2 of the bolts holding the cap on.
> (They were rusty and broke). I was expecting the removal of the
> distributor to be harder, but it was pretty much idiot proof. It
> appears that you can only put the distributor back in the block either
> the correct way or 180 degrees wrong. So if you are careful, you
> should be OK.
>
> Also, since my distributor had never been removed before, it was easy
> to put it back exactly the way I had removed it as I could see where
> the washers for the adjustment bolts had been before (good old
> corrosion at work here again). Checked the timing with a timing light
> after, and all is well.
>
> Note that the idle fluctuations occured before I did the tune up work
> (which was overdue anyway).
>
> I am also fairly certain the car is running pretty rich.

ECU trouble codes? your's is an OBD-2 model.

> Fuel economy
> is relatively poor (around 11-13km/liter or 25-30 US MPG or 31-36 UK
> MPG), and the exhaust pipe is pretty black. I have run several
> bottles of injector cleaner and Lucas Oil Upper Cylinder lubricant
> over the past few tanks and seen no real improvement here.
>
> The car has great performance, when you want to step into it, it
> accelerates really well. However, I have also measured fuel economy
> on a light foot, and the mileage is about the same.
>
> Driving pattern is mostly highway, we live about 20km outside the
> city.
>
> Any ideas of what I could check would be greatly appreciated.
>
> Thanks
> Terry in Winnipeg
>

you're probably overdue for a new O2 sensor(they last ~60-100K miles),and
you need to get the ECU trouble codes read;a rich condition should set a
code,light up the MIL light.
Perhaps a bad throttle position sensor for the idle problem?

--
Jim Yanik
jyanik
at
kua.net

I agree the 1200-1500 is way too high.

No trouble codes, I have a code reader.

Plug wires have less than 100k kms on them. They are lifetime warranty bosch,
and I did a continuity test and a resistance test on them, they are good.

Where is the switch for the AC? I need to test it.

I will check the TPS. any pointers?

Thanks
t


Jim Yanik wrote:
>> Good day,
>>
>[quoted text clipped - 3 lines]
>> red light, my RPMs stay at around 2500. After a few seconds, or if I
>> pump the gas pedal, the RPMs go down to about 1200-1500.
>
>Still too high.
>
>> This just recently started happening. Don't know if its related, my
>> AC recently stopped cooling. Sounds like the compressor doesn't come
>> on. Is there anything in the AC mechanism that affects idle speed?
>
>A switch to tell the ECU to increase the idle.
>
>> Also, have recently done the following, all with OEM parts from the
>> dealership:
>>
>> Spark plugs
>> Distributor Cap
>> Distributor Rotor
>
>No plug wires? They don't last forever.
>
>> PCV valve
>> Air Filter
>[quoted text clipped - 21 lines]
>>
>> I am also fairly certain the car is running pretty rich.
>
>ECU trouble codes? your's is an OBD-2 model.
>
>> Fuel economy
>> is relatively poor (around 11-13km/liter or 25-30 US MPG or 31-36 UK
>[quoted text clipped - 13 lines]
>> Thanks
>> Terry in Winnipeg
>
>you're probably overdue for a new O2 sensor(they last ~60-100K miles),and
>you need to get the ECU trouble codes read;a rich condition should set a
>code,light up the MIL light.
>Perhaps a bad throttle position sensor for the idle problem?
>

--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...-cars/200710/1

are my symptoms indicative of a MAP sensor failure?

t

loewent wrote:
>I agree the 1200-1500 is way too high.
>
>No trouble codes, I have a code reader.
>
>Plug wires have less than 100k kms on them. They are lifetime warranty bosch,
>and I did a continuity test and a resistance test on them, they are good.
>
>Where is the switch for the AC? I need to test it.
>
>I will check the TPS. any pointers?
>
>Thanks
>t
>
>>> Good day,
>>>
>[quoted text clipped - 37 lines]
>>code,light up the MIL light.
>>Perhaps a bad throttle position sensor for the idle problem?

--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...-cars/200710/1

loewent via CarKB.com wrote:
> are my symptoms indicative of a MAP sensor failure?
>
------------------------------

I think you've got air in your cooling system. I'd fill the reservoir to
MAX and observe where it is each morning. Add more until is stays at MAX
each morning.

When the coolant temp sensors are high-n-dry, the computer has no idea
where to set the timing / mixture.

'Curly'

Went for lunch and this is what I observed:

RPMs = ~1800 when cold.

After driving for 10 minutes, RPMs were around 1800-2200.

I got to my lunch spot, and turned the car off. Then started it immediately.
RPMs were at 600-700 (normal). Then I turned it off and went for lunch.

Coming back to work, the RPMs were back up at around 1500-1800. When I got
to my parking spot, I popped the hood and fiddled with the throttle a bit.
By turning the throttle I was able to get the RPMs down to 600. So I'm
wondering if this is a problem in the throttle body?

As far as the coolant, all appears normal, rad is full to the top and
resevoir is a little below normal. I haven't done any work on the cooling
system for quite some time, so I doubt that an air pocket would develop
spontaneously. I'll keep an eye on it.

t

motsco_ wrote:
>> are my symptoms indicative of a MAP sensor failure?
>
>------------------------------
>
>I think you've got air in your cooling system. I'd fill the reservoir to
>MAX and observe where it is each morning. Add more until is stays at MAX
>each morning.
>
>When the coolant temp sensors are high-n-dry, the computer has no idea
>where to set the timing / mixture.
>
>'Curly'

--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...-cars/200710/1

"loewent via CarKB.com" <u10197@uwe> wrote in news:792417cc18b54@uwe:

> Good day,
>
> 98 civic LX 5 spd with 285000kms.
>
> After being on the highway during my 35km commute, when I pull up at a
> red light, my RPMs stay at around 2500. After a few seconds, or if I
> pump the gas pedal, the RPMs go down to about 1200-1500.


Have a look at your injectors. Do you have air lines running to each
injector?

How clean is your throttle body?

How old is your thermostat?


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"loewent via CarKB.com" <u10197@uwe> wrote in news:792600324f1de@uwe:

> Went for lunch and this is what I observed:
>
> RPMs = ~1800 when cold.
>
> After driving for 10 minutes, RPMs were around 1800-2200.
>
> I got to my lunch spot, and turned the car off. Then started it
> immediately. RPMs were at 600-700 (normal). Then I turned it off and
> went for lunch.
>
> Coming back to work, the RPMs were back up at around 1500-1800. When
> I got to my parking spot, I popped the hood and fiddled with the
> throttle a bit. By turning the throttle I was able to get the RPMs
> down to 600. So I'm wondering if this is a problem in the throttle
> body?

Maybe the throttle body has varnish built up and is keeping the plate open
more occasionally? A thorough cleaning would correct that.
Have you ohmed the TPS sensor? It could be getting worn at the "closed" end
of the pot.
>
> As far as the coolant, all appears normal, rad is full to the top and
> resevoir is a little below normal. I haven't done any work on the
> cooling system for quite some time, so I doubt that an air pocket
> would develop spontaneously. I'll keep an eye on it.
>
> t
>
> motsco_ wrote:
>>> are my symptoms indicative of a MAP sensor failure?

there are ohms tests for MAP sensors.

>>
>>------------------------------
>>
>>I think you've got air in your cooling system. I'd fill the reservoir
>>to MAX and observe where it is each morning. Add more until is stays
>>at MAX each morning.
>>
>>When the coolant temp sensors are high-n-dry, the computer has no idea
>>where to set the timing / mixture.

I had a CTS open on my 94 Integra GS-R.
It's just a thermistor,an ohmmeter will verify it.
Service manuals should list the ohms ranges for the various sensors.


I'd like to note that O2 sensors can get "slow" near the end of their
life,and not set a trouble code,but still affect operation.

--
Jim Yanik
jyanik
at
kua.net

Got some Throttle body cleaner, sprayed the throttle plate and tube. Also
lubed the throttle spring where the cable attaches. Seems to be OK now.

Is there a way to test my O2 sensors to see if they are bad? (or slow as you
put it)

Jim Yanik wrote:
>> Went for lunch and this is what I observed:
>>
>[quoted text clipped - 11 lines]
>> down to 600. So I'm wondering if this is a problem in the throttle
>> body?
>
>Maybe the throttle body has varnish built up and is keeping the plate open
>more occasionally? A thorough cleaning would correct that.
>Have you ohmed the TPS sensor? It could be getting worn at the "closed" end
>of the pot.
>
>> As far as the coolant, all appears normal, rad is full to the top and
>> resevoir is a little below normal. I haven't done any work on the
>[quoted text clipped - 4 lines]
>>
>>>> are my symptoms indicative of a MAP sensor failure?
>
>there are ohms tests for MAP sensors.
>
>>>------------------------------
>>>
>[quoted text clipped - 4 lines]
>>>When the coolant temp sensors are high-n-dry, the computer has no idea
>>>where to set the timing / mixture.
>
>I had a CTS open on my 94 Integra GS-R.
>It's just a thermistor,an ohmmeter will verify it.
>Service manuals should list the ohms ranges for the various sensors.
>
>I'd like to note that O2 sensors can get "slow" near the end of their
>life,and not set a trouble code,but still affect operation.
>

--
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