1994 Honda Civic Stumbling
 

I have a Honda Civic LX 1994 that stumbles on acceleration. It seems
to be worse when it is warm. It feels like only one of the cylinders
misfires while accelerating, making the car lack power and vibrate, and
once the RPMS get high enough, at around 3000RPMS, the misfiring
dissapears. Nonetheless, it is a combination of the engine load versus
the RPMs, I can get it to stuble at any given RPM setting, if I press
on the throttle pedal too hard. Here are the parts I have now replaced:

Entire distributor, including the cap and rotor.
Spark Plug Wires
Spark Plugs
Fuel Pump and fuel strainer
Fuel Filter
Fuel Rail
All 4 Injectors
Fuel Regulator
Air filter

I have checked the TPS with a multimeter, 0.5V at closed throttle and
4.5V at full throttle smooth transition in between.
I have tested the MAP sensor with a hand vacumm gauge and a multimeter,
sensor is all nominal but here is the chart if anyone cares to look at
it:
0psi 2.80V
5psi 2.34V
10psi 1.86V
15psi 1.39V
20psi 0.96V
25psi 0.52V
I have tested the fuel pressure, pressure is normal.
I have tested the O2 sensor with a multimeter and propane torch. Again
it seems to be normal. I have also disconnected it from the car and
driven it without the lambda sensor, still the car behaves the same and
stumbles.
I have checked the timing with a timing light, and the timing is right
on according to specification.
The ECM reports no trouble codes. The ECM reports no "Check Engine"
light while driving, although the car stumbles wildly.
I am running out of ideas... can anyone think of anything else I should
check or that could possibly be the reason for the car stumbling.

- JR

Re: 1994 Honda Civic Stumbling
 

A few more basics to check or do:

-- Dump a bottle of Chevron Techron fuel system cleaner into
the car's near empty fuel tank. Fill with gas.

-- Check the ignition timing.

-- A bad O2 sensor will not necessarily set off a CEL on a
1994 Honda (pre-OBD2). Since the problem occurs after
warmup, that makes me especially suspicious of the O2
sensor. https://www.automedicsupply.com/ has the best
prices I've seen for OEM O2 sensors: About $69 altogether. I
have used them. Good, prompt service. Maybe not a bad
investment for a car this old.

-- Purge cooling system thoroughly of air. Follow the
manual's instructions. Getting the fan to come on may take
as much as 40 minutes of idling. If various ECM sensors
aren't cooled properly, then this may cause erratic
behavior.

Are all the ignition parts (plugs, wires, distributor etc.)
OEM?

<jrlomas@sgintl.com> wrote
>I have a Honda Civic LX 1994 that stumbles on acceleration.
>It seems
> to be worse when it is warm. It feels like only one of
> the cylinders
> misfires while accelerating, making the car lack power and
> vibrate, and
> once the RPMS get high enough, at around 3000RPMS, the
> misfiring
> dissapears. Nonetheless, it is a combination of the
> engine load versus
> the RPMs, I can get it to stuble at any given RPM setting,
> if I press
> on the throttle pedal too hard. Here are the parts I have
> now replaced:
>
> Entire distributor, including the cap and rotor.
> Spark Plug Wires
> Spark Plugs
> Fuel Pump and fuel strainer
> Fuel Filter
> Fuel Rail
> All 4 Injectors
> Fuel Regulator
> Air filter
>
> I have checked the TPS with a multimeter, 0.5V at closed
> throttle and
> 4.5V at full throttle smooth transition in between.
> I have tested the MAP sensor with a hand vacumm gauge and
> a multimeter,
> sensor is all nominal but here is the chart if anyone
> cares to look at
> it:
> 0psi 2.80V
> 5psi 2.34V
> 10psi 1.86V
> 15psi 1.39V
> 20psi 0.96V
> 25psi 0.52V
> I have tested the fuel pressure, pressure is normal.
> I have tested the O2 sensor with a multimeter and propane
> torch. Again
> it seems to be normal. I have also disconnected it from
> the car and
> driven it without the lambda sensor, still the car behaves
> the same and
> stumbles.
> I have checked the timing with a timing light, and the
> timing is right
> on according to specification.
> The ECM reports no trouble codes. The ECM reports no
> "Check Engine"
> light while driving, although the car stumbles wildly.
> I am running out of ideas... can anyone think of anything
> else I should
> check or that could possibly be the reason for the car
> stumbling.
>
> - JR
>

Re: 1994 Honda Civic Stumbling
 

jrlomas@sgintl.com wrote:

> I have a Honda Civic LX 1994 that stumbles on acceleration. It seems
> to be worse when it is warm. It feels like only one of the cylinders
> misfires while accelerating, making the car lack power and vibrate,
> and once the RPMS get high enough, at around 3000RPMS, the misfiring
> dissapears.



You haven't indicated your transmission. Auto or manual?

Might be an EGR valve sticking partly open. Have you checked for this?

Re: 1994 Honda Civic Stumbling
 

Hugo Schmeisser wrote:
> jrlomas@sgintl.com wrote:
>
> > I have a Honda Civic LX 1994 that stumbles on acceleration. It seems
> > to be worse when it is warm. It feels like only one of the cylinders
> > misfires while accelerating, making the car lack power and vibrate,
> > and once the RPMS get high enough, at around 3000RPMS, the misfiring
> > dissapears.
>
>
>
> You haven't indicated your transmission. Auto or manual?
>
> Might be an EGR valve sticking partly open. Have you checked for this?

The car has no EGR system. The car has a manual 5 speed transmission.

- JR

Re: 1994 Honda Civic Stumbling
 

Like I said, the O2 sensors tests OK. I have unplugged the sensor and
driven without it, only to experience the same problem. The O2 sensor
has only 20,000 miles on it. It was put in six months ago; Bosh made.
All other replaced parts are OEM.

- JR

Re: 1994 Honda Civic Stumbling
 

jrlomas@sgintl.com wrote:
>
> Like I said, the O2 sensors tests OK. I have unplugged the sensor and
> driven without it, only to experience the same problem. The O2 sensor
> has only 20,000 miles on it. It was put in six months ago; Bosh made.
> All other replaced parts are OEM.
>
> - JR


------------------------------

What's the mileage on the vehicle? Did this problem show up after your
last Timing Belt replacement? Were the valves adjusted at the same time?

P.S. Almost everybody agrees that Bosch O2 sensors shouldn't be used on
Hondas :-( Same for their plugs.

'Curly'

Re: 1994 Honda Civic Stumbling
 

I have personally rebuilt the engine... the problem did not show up
after the timing belt replacement, which happened at the time the
engine was replaced. All of the major compenents in the car were
changed in 20,000 miles ago, along with the entire motor. The car has
been running just great until now.

> Almost everybody agrees that Bosch O2 sensors shouldn't be used on Hondas.
Even then, unplugging the 02 sensor, the car experiences exactly the
same problem I have described.

Re: 1994 Honda Civic Stumbling
 

The problem occurs at all times, it just happens to be MORE pronounced
when warm than cold.
As I have said before, I have cheked the timing and it is right on the
spot.
Following your suggestion I have gone through the air purging on the
coolings system (which did not need to be purged by the way). No
change.
Thank you for your suggestions.

- JR

Re: 1994 Honda Civic Stumbling
 

jrlomas@sgintl.com wrote:
>
> I have personally rebuilt the engine... the problem did not show up
> after the timing belt replacement, which happened at the time the
> engine was replaced. All of the major compenents in the car were
> changed in 20,000 miles ago, along with the entire motor. The car has
> been running just great until now.
>
> > Almost everybody agrees that Bosch O2 sensors shouldn't be used on Hondas.
> Even then, unplugging the 02 sensor, the car experiences exactly the
> same problem I have described.


-----------------------------

How far back (days / months/ miles) does the term "running just great
until now" go back? Last fill of gas?

After you got the engine re-installed, did you find that you had to move
the distributor about 10 degrees to get the ignition timing correct? If
so, I'd guess that the cam timing is out, but the ignition timing is
correct(ed). Do you have to put the jumper on the ECM connection when
you time a '94, like you do for the newer (OBDII) ones?

Is the new engine an exact match to the car, or did you import the ECM
as well?

'Curly'

Re: 1994 Honda Civic Stumbling
 

Running great until 100 miles ago. Running well for 20,000 miles after
rebuild.
I didn't have to do anything special except point the gun and align the
lines on the crank pulley with the alignment mark on the timing cover.
You DO have to jumper the connections with a a jumper wire, and you
have to wait until the engine has come to normal temperature to do the
timing.
The engine is an exact match to the car.

- JR

Re: 1994 Honda Civic Stumbling
 

jrlomas@sgintl.com wrote:
> Running great until 100 miles ago. Running well for 20,000 miles after
> rebuild.
> I didn't have to do anything special except point the gun and align the
> lines on the crank pulley with the alignment mark on the timing cover.
> You DO have to jumper the connections with a a jumper wire, and you
> have to wait until the engine has come to normal temperature to do the
> timing.
> The engine is an exact match to the car.

How about a compression test?

Re: 1994 Honda Civic Stumbling
 

Interesting answer... I never thought the problem could be mechanical.
I will run a compression test. I will let you guys know.

Re: 1994 Honda Civic Stumbling
 

Alan wrote:
> jrlomas@sgintl.com wrote:
>
>>Running great until 100 miles ago. Running well for 20,000 miles after
>>rebuild.
>>I didn't have to do anything special except point the gun and align the
>>lines on the crank pulley with the alignment mark on the timing cover.
>>You DO have to jumper the connections with a a jumper wire, and you
>>have to wait until the engine has come to normal temperature to do the
>>timing.
>>The engine is an exact match to the car.
>
>
> How about a compression test?
>
i second that. unless this is something really rudimentary like a
vacuum hose has fallen off, a burnt inlet valve is a good candidate for
the symptoms described. it should be very distinctive on cold cranking
though - instead of 4 even compression cycles, one will "wow" much
faster than the rest.

Re: 1994 Honda Civic Stumbling
 

<jrlomas@sgintl.com> wrote
>I have personally rebuilt the engine... the problem did not
>show up
> after the timing belt replacement, which happened at the
> time the
> engine was replaced. All of the major compenents in the
> car were
> changed in 20,000 miles ago, along with the entire motor.
> The car has
> been running just great until now.
>
>> Almost everybody agrees that Bosch O2 sensors shouldn't
>> be used on Hondas.
> Even then, unplugging the 02 sensor, the car experiences
> exactly the
> same problem I have described.

That's not dispositive.

I personally would not yet eliminate the O2 sensor. That
it's Bosch certainly makes me suspicious.

Two cents.

Re: 1994 Honda Civic Stumbling
 

jrlomas@sgintl.com wrote:
> Interesting answer... I never thought the problem could be mechanical.
> I will run a compression test. I will let you guys know.

I don't know if a bad ring would do that or not.

Re: 1994 Honda Civic Stumbling
 

I've got a '90 Civic doing the same thing. I was thinking that my
timing wasn't advancing right.
Anybody know what makes the timing advance?
Did you try running the car with a jumper wire in the connector for
testing the timing? Would that show anything?

-supa

Re: 1994 Honda Civic Stumbling
 

Alan wrote:
> jrlomas@sgintl.com wrote:
> > Interesting answer... I never thought the problem could be mechanical.
> > I will run a compression test. I will let you guys know.
>
> I don't know if a bad ring would do that or not.

I doubt a ring would cause the problem; though I will certainly check.
The car does not burn any oil.

Re: 1994 Honda Civic Stumbling
 

What causes an inlet valve to burn? I am at work now, but I will run a
compression test later this evening. I will let you guys know the
results. All of you have been very useful... at least I feel I am
going somewhere trying to diagnose the problem.

Re: 1994 Honda Civic Stumbling
 

<jrlomas@sgintl.com> wrote in message
news:1142870641.980151.268390@e56g2000cwe.googlegr oups.com...
> What causes an inlet valve to burn? I am at work now, but I will run a
> compression test later this evening. I will let you guys know the
> results. All of you have been very useful... at least I feel I am
> going somewhere trying to diagnose the problem.
>
The usual cause is inadequate valve lash. If the rockers are too tight the
valve will leak and the combustion gasses will torch a channel in the valve.
That should show up on the compression test, although it may not be shocking
yet.

Mike

Re: 1994 Honda Civic Stumbling
 

I am curious as to whether he has gauged the voltage from the coils at
the spark plugs.
If I've read correctly, he can get the misfire to occur at will by
increasing throttle pressure relative to extant engine RPM--in other
words, putting enough load on the engine--to the point of the voltage
being insufficient to ignite charge.
For what it's worth, it is also within the realm of possibility that
the engine controller itself it the culprit, hence no MIL (check engine
light).
Note that I'm not experienced with Hondas in particular, I'm just
throwing this out as my 2ç.
New to this group (looking at a Honda in a car lot)! :0)

Re: 1994 Honda Civic Stumbling
 

I had an old K car that would misfire under a load. I would briefly
test it by one foot on the brake and the other on the gas. The culprit
was a bad or weak coil.

James Goforth wrote:
> I am curious as to whether he has gauged the voltage from the coils at
> the spark plugs.
> If I've read correctly, he can get the misfire to occur at will by
> increasing throttle pressure relative to extant engine RPM--in other
> words, putting enough load on the engine--to the point of the voltage
> being insufficient to ignite charge.
> For what it's worth, it is also within the realm of possibility that
> the engine controller itself it the culprit, hence no MIL (check engine
> light).
> Note that I'm not experienced with Hondas in particular, I'm just
> throwing this out as my 2ç.
> New to this group (looking at a Honda in a car lot)! :0)

Re: 1994 Honda Civic Stumbling
 

"Alan" <twobutnot2@comcast.net> wrote in
news:1142994848.517630.271720@z34g2000cwc.googlegr oups.com:

>
> I had an old K car that would misfire under a load. I would briefly
> test it by one foot on the brake and the other on the gas. The culprit
> was a bad or weak coil.


Considering that Honda/Acura autos are known for failing ignition
coils,this would be a good place to start.


--
Jim Yanik
jyanik
at
kua.net

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

Elle wrote:

........A bad O2 sensor will not necessarily set off a CEL on a
1994 Honda (pre-OBD2). Since the problem occurs after
warmup, that makes me especially suspicious of the O2
sensor. https://www.automedicsupply.com/ has the best
prices I've seen for OEM O2 sensors: About $69 altogether. I
have used them. Good, prompt service. Maybe not a bad
investment for a car this old.

Elle, I went to this site, & an O2 sensor for my 94 VX is $289.99.
Before I spend this much money, what symptoms would I be
seeing?


......Purge cooling system thoroughly of air. Follow the
manual's instructions. Getting the fan to come on may take
as much as 40 minutes of idling. If various ECM sensors
aren't cooled properly, then this may cause erratic
behavior.

I'm following the manual for a 92 Civic, & reference a 95 PDF
which is identical. I've pulled & cleaned the reservoir, then
replaced. It appears the radiator drain plug turns counter
clockwise. Any hints on how to get it to move without breaking
it?

I started the car, put the heater temp control lever to max heat, then
shut off the engine. No mention of whether or not to have the fan
running while I purge the system. Any ideas? I'll top up the
fluid today, then once I can get the drain plug to move, do a complete
refill.

I've tried bleeding before, but had the cap completely off. Manual says
to put it on to the 1st stop. I was still getting the erratic idle at a
stop
with this approach.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

Elle wrote:

........A bad O2 sensor will not necessarily set off a CEL on a
1994 Honda (pre-OBD2). Since the problem occurs after
warmup, that makes me especially suspicious of the O2
sensor. https://www.automedicsupply.com/ has the best
prices I've seen for OEM O2 sensors: About $69 altogether. I
have used them. Good, prompt service. Maybe not a bad
investment for a car this old.

Elle, I went to this site, & an O2 sensor for my 94 VX is $289.99.
Before I spend this much money, what symptoms would I be
seeing?


......Purge cooling system thoroughly of air. Follow the
manual's instructions. Getting the fan to come on may take
as much as 40 minutes of idling. If various ECM sensors
aren't cooled properly, then this may cause erratic
behavior.

I'm following the manual for a 92 Civic, & reference a 95 PDF
which is identical. I've pulled & cleaned the reservoir, then
replaced. It appears the radiator drain plug turns counter
clockwise. Any hints on how to get it to move without breaking
it?

I started the car, put the heater temp control lever to max heat, then
shut off the engine. No mention of whether or not to have the fan
running while I purge the system. Any ideas? I'll top up the
fluid today, then once I can get the drain plug to move, do a complete
refill.

I've tried bleeding before, but had the cap completely off. Manual says
to put it on to the 1st stop. I was still getting the erratic idle at a
stop
with this approach.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

"Mike Doyle" <sigifrith@frontiernet.net> wrote
> Elle wrote:
>
> .......A bad O2 sensor will not necessarily set off a CEL
> on a
> 1994 Honda (pre-OBD2). Since the problem occurs after
> warmup, that makes me especially suspicious of the O2
> sensor. https://www.automedicsupply.com/ has the best
> prices I've seen for OEM O2 sensors: About $69 altogether.
> I
> have used them. Good, prompt service. Maybe not a bad
> investment for a car this old.
>
> Elle, I went to this site, & an O2 sensor for my 94 VX is
> $289.99.

Oops, sorry. The 94 Sensors seem to be far less for any
Civic that is not a VX.

Still, this price beats www.hondaautomotiveparts.com , at
$340 + s/h.

> Before I spend this much money, what symptoms would I be
> seeing?

If after performing a tuneup (new plugs, possibly new
ignition wires, new distributor cap and rotor, new air
filter, new fuel filter, check timing), the stumbling and/or
poor gas mileage continues, I would consider a new O2
sensor.

> .....Purge cooling system thoroughly of air. Follow the
> manual's instructions. Getting the fan to come on may take
> as much as 40 minutes of idling. If various ECM sensors
> aren't cooled properly, then this may cause erratic
> behavior.
>
> I'm following the manual for a 92 Civic, & reference a 95
> PDF
> which is identical. I've pulled & cleaned the reservoir,
> then
> replaced. It appears the radiator drain plug turns
> counter
> clockwise.

Yes it does. The usual rightie-tightie lefty-loosy threads.

> Any hints on how to get it to move without breaking
> it?

IIRC sometimes it's very tight. I have used a pair of pliers
on its end to get a good grip.

Might be a good idea to buy a spare from your dealer in
advance in case it does break. Though I haven't heard of one
breaking.

> I started the car, put the heater temp control lever to
> max heat, then
> shut off the engine. No mention of whether or not to have
> the fan
> running while I purge the system.

Leave the passenger car fan off.

> Any ideas? I'll top up the
> fluid today, then once I can get the drain plug to move,
> do a complete
> refill.
>
> I've tried bleeding before, but had the cap completely
> off. Manual says
> to put it on to the 1st stop.

I would perform (and do perform) the bleed with the cap
completely off. I too noticed a similar discrepancy between
what's in my Chilton's manual and what's in my owner's
manual for this procedure. I see the service manuals at the
site below say to leave the cap completely off for the CRX.
(I think the Concerto manual has a typ-o on this point.)

It makes more sense to me to have the system under the
lowest pressure possible so as to encourage air to escape
it.

> I was still getting the erratic idle at a stop
> with this approach.

Try the Concerto manual at
http://www.honda.co.uk/car/owner/workshop.html, under "Fuel
and Emissions" then under "Idle control system," for other
things to check, especially the Electronic Air Control
Valve. This group gets a few reports of this failing every
year (assuming the air purge above doesn't fix the problem).

Can you clarify: Is the car both stumbling while
accelerating and has an erratic idle?

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

"Mike Doyle" <sigifrith@frontiernet.net> wrote
> Elle wrote:
>
> .......A bad O2 sensor will not necessarily set off a CEL
> on a
> 1994 Honda (pre-OBD2). Since the problem occurs after
> warmup, that makes me especially suspicious of the O2
> sensor. https://www.automedicsupply.com/ has the best
> prices I've seen for OEM O2 sensors: About $69 altogether.
> I
> have used them. Good, prompt service. Maybe not a bad
> investment for a car this old.
>
> Elle, I went to this site, & an O2 sensor for my 94 VX is
> $289.99.

Oops, sorry. The 94 Sensors seem to be far less for any
Civic that is not a VX.

Still, this price beats www.hondaautomotiveparts.com , at
$340 + s/h.

> Before I spend this much money, what symptoms would I be
> seeing?

If after performing a tuneup (new plugs, possibly new
ignition wires, new distributor cap and rotor, new air
filter, new fuel filter, check timing), the stumbling and/or
poor gas mileage continues, I would consider a new O2
sensor.

> .....Purge cooling system thoroughly of air. Follow the
> manual's instructions. Getting the fan to come on may take
> as much as 40 minutes of idling. If various ECM sensors
> aren't cooled properly, then this may cause erratic
> behavior.
>
> I'm following the manual for a 92 Civic, & reference a 95
> PDF
> which is identical. I've pulled & cleaned the reservoir,
> then
> replaced. It appears the radiator drain plug turns
> counter
> clockwise.

Yes it does. The usual rightie-tightie lefty-loosy threads.

> Any hints on how to get it to move without breaking
> it?

IIRC sometimes it's very tight. I have used a pair of pliers
on its end to get a good grip.

Might be a good idea to buy a spare from your dealer in
advance in case it does break. Though I haven't heard of one
breaking.

> I started the car, put the heater temp control lever to
> max heat, then
> shut off the engine. No mention of whether or not to have
> the fan
> running while I purge the system.

Leave the passenger car fan off.

> Any ideas? I'll top up the
> fluid today, then once I can get the drain plug to move,
> do a complete
> refill.
>
> I've tried bleeding before, but had the cap completely
> off. Manual says
> to put it on to the 1st stop.

I would perform (and do perform) the bleed with the cap
completely off. I too noticed a similar discrepancy between
what's in my Chilton's manual and what's in my owner's
manual for this procedure. I see the service manuals at the
site below say to leave the cap completely off for the CRX.
(I think the Concerto manual has a typ-o on this point.)

It makes more sense to me to have the system under the
lowest pressure possible so as to encourage air to escape
it.

> I was still getting the erratic idle at a stop
> with this approach.

Try the Concerto manual at
http://www.honda.co.uk/car/owner/workshop.html, under "Fuel
and Emissions" then under "Idle control system," for other
things to check, especially the Electronic Air Control
Valve. This group gets a few reports of this failing every
year (assuming the air purge above doesn't fix the problem).

Can you clarify: Is the car both stumbling while
accelerating and has an erratic idle?

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

"Elle" <honda.lioness@nospam.earthlink.net> wrote
> Leave the passenger car fan off.

I meant the "passenger compartment blower" should be left
off.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

"Elle" <honda.lioness@nospam.earthlink.net> wrote
> Leave the passenger car fan off.

I meant the "passenger compartment blower" should be left
off.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

Elle wrote:
...... Can you clarify: Is the car both stumbling while
accelerating and has an erratic idle?


Acceleration is fine for a VX. It's sitting at a light, or
stop sign with all accessories off. The car doesn't die,
but the idle tends to drop low enough that I think it
will. Turning the fan on to it's lowest setting stops this,
but thats just masking the problem.

I bought it in August. So far, I've replaced the plugs &
wires with OE. Put on an after market fuel filter. Honda
dealer replaced the timing belt & water pump. I've
added an after market cruise control. Not sure if it would
cause any trouble. I've had them on all my other 3 Civics.
Just passed 200K on a trip to Texas. 40+ MPG since I
bought it.

I went ahead & replaced the Antifreeze today. Careful
use of some water pump pliers loosened the drain valve.
I'll keep a close watch on the overflow reservoir this week.
30+ miles each way to work, so hopefully any remaining
air will be purged.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

Elle wrote:
...... Can you clarify: Is the car both stumbling while
accelerating and has an erratic idle?


Acceleration is fine for a VX. It's sitting at a light, or
stop sign with all accessories off. The car doesn't die,
but the idle tends to drop low enough that I think it
will. Turning the fan on to it's lowest setting stops this,
but thats just masking the problem.

I bought it in August. So far, I've replaced the plugs &
wires with OE. Put on an after market fuel filter. Honda
dealer replaced the timing belt & water pump. I've
added an after market cruise control. Not sure if it would
cause any trouble. I've had them on all my other 3 Civics.
Just passed 200K on a trip to Texas. 40+ MPG since I
bought it.

I went ahead & replaced the Antifreeze today. Careful
use of some water pump pliers loosened the drain valve.
I'll keep a close watch on the overflow reservoir this week.
30+ miles each way to work, so hopefully any remaining
air will be purged.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

"Mike Doyle" <sigifrith@frontiernet.net> wrote
> Elle wrote:
> ..... Can you clarify: Is the car both stumbling while
> accelerating and has an erratic idle?
>
>
> Acceleration is fine for a VX. It's sitting at a light,
> or
> stop sign with all accessories off. The car doesn't die,
> but the idle tends to drop low enough that I think it
> will. Turning the fan on to it's lowest setting stops
> this,
> but thats just masking the problem.

This doesn't sound like the oxygen sensor.

It is worth checking the ignition coil, especially if this
occurs after the engine is warmed up, like after 20 minutes
of driving. An older ignition coil will be persnickety at
idle, especially at warmup. Ultimately it will fail
completely.

See info on checks you can do on the coil at
http://www.tegger.com/hondafaq/start...s.html#badcoil

> I bought it in August. So far, I've replaced the plugs &
> wires with OE.

I would replace the cap and rotor, too.

Put on an after market fuel filter. Honda
> dealer replaced the timing belt & water pump. I've
> added an after market cruise control. Not sure if it
> would
> cause any trouble. I've had them on all my other 3
> Civics.
> Just passed 200K on a trip to Texas. 40+ MPG since I
> bought it.
>
> I went ahead & replaced the Antifreeze today. Careful
> use of some water pump pliers loosened the drain valve.
> I'll keep a close watch on the overflow reservoir this
> week.
> 30+ miles each way to work, so hopefully any remaining
> air will be purged.

I'm not sure that's the same as getting the car temp up high
enough to get the fan to come on twice, with the rad cap
off.

I changed my 91 Civic's thermostat in March 04 and did not
do a proper purge. I started having idle problems around
July or so. I found the cooling lines to the EACV empty. It
seems to be a high spot. A proper purge fixed the problem.

Re: 1994 Honda Civic Stumbling, Now Random ?'s
 

"Mike Doyle" <sigifrith@frontiernet.net> wrote
> Elle wrote:
> ..... Can you clarify: Is the car both stumbling while
> accelerating and has an erratic idle?
>
>
> Acceleration is fine for a VX. It's sitting at a light,
> or
> stop sign with all accessories off. The car doesn't die,
> but the idle tends to drop low enough that I think it
> will. Turning the fan on to it's lowest setting stops
> this,
> but thats just masking the problem.

This doesn't sound like the oxygen sensor.

It is worth checking the ignition coil, especially if this
occurs after the engine is warmed up, like after 20 minutes
of driving. An older ignition coil will be persnickety at
idle, especially at warmup. Ultimately it will fail
completely.

See info on checks you can do on the coil at
http://www.tegger.com/hondafaq/start...s.html#badcoil

> I bought it in August. So far, I've replaced the plugs &
> wires with OE.

I would replace the cap and rotor, too.

Put on an after market fuel filter. Honda
> dealer replaced the timing belt & water pump. I've
> added an after market cruise control. Not sure if it
> would
> cause any trouble. I've had them on all my other 3
> Civics.
> Just passed 200K on a trip to Texas. 40+ MPG since I
> bought it.
>
> I went ahead & replaced the Antifreeze today. Careful
> use of some water pump pliers loosened the drain valve.
> I'll keep a close watch on the overflow reservoir this
> week.
> 30+ miles each way to work, so hopefully any remaining
> air will be purged.

I'm not sure that's the same as getting the car temp up high
enough to get the fan to come on twice, with the rad cap
off.

I changed my 91 Civic's thermostat in March 04 and did not
do a proper purge. I started having idle problems around
July or so. I found the cooling lines to the EACV empty. It
seems to be a high spot. A proper purge fixed the problem.