1990 Civic Power Loss and Shudders

I have a 1990 Honda Civic 4 door with 196k. The car has been running great.
The car now seems to have a power loss at low rpm and jerks and shudders
untill about 3000 rpm when it will kick back in and perform. I have
changed the fuel filter, have new plugs, wires, dist/cap/rotor and all my
vac lines appear in good shape. Anybody delt with this please drop a line.

 

EGR valve sticking open?

Oh, Terry, where are you?!

 

try the thermostat. it you're still on the original, it'll almost
certainly be out of spec. by now. mine was & changing it removed
symptoms like you describe. also check the operation of the throttle
body's tandem valve.

 

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

What's the details on your timing belt . . It sounds like it's off a
tooth or two. Is it better once the engine warms up, or just the same?

'Curly'

 

Not sure about the timing belt. That is something that I don't have
knowledge of. The two other posts metioned EGR and Tandem Valves. The
tandem appears to be fine but I can't locate the EGR.

 

Where is the EGR on this car? Guess I should buy another Haynes manuel.

 

Where are you located? I think a lot of US models from that vintage do
not have the EGR if they are not California models. Possibly one trim
line does have it regardless of being a Cali model, maybe the STD (hatch
only trim). I'm not sure though. My '91 Si does not have an EGR valve.

Mark

 

Also, check to make sure that the timing advance mechanisms in the
distributer are working properly.

 

The automatic had EGR, the manual did not. True for all states and Canada.

 

(Gordon McGrew) wrote in

You mean like vacuum advance and centrifugal weights? Ain't no such thing
in the '90 Civic.

 

TeGGer wrote:
TeGGer® Apr 12, 6:08 pm show options
Newsgroups: rec.autos.makers.honda
From: "TeGGer®" <0m> - Find messages by this author
Date: 13 Apr 2005 01:08:05 GMT
Local: Tues,Apr 12 2005 6:08 pm
Subject: Re: 1990 Civic Power Loss and Shudders
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EGR valve sticking open?

Oh, Terry, where are you?!

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/
----------------------------------------
I have seen an ignitor module casue this behavior, and a ECM (ECU)
cause similar problems. The ignitor is pretty cheap to change, the
CPU is rather pricy, about $150 and there is no easy way to check
the ECM for this type problem/. The bad unit presented no error codes
and at highway speeds ran great.
I initally suspect the TDC because it had a slightly lower output then
a friends 90 Civic. But swapping the ECM cured it. I considered
changing
the TDC but the owner needed to go on a trip, so I never got the
chance.

I would be tempted to run a can of good injector cleaner, with good
(Cevron) gas through it before spending any real money.

As anohter poster menetioned the thermostat could cause this problem,
but you should notice either low or high engine temp. Check your fluid
levels.

If it is a AT, as Tigger pointed out the EGR could be a problem.
I have seen a Subaru with a partially stuck EGR that would only run
welonce it was above about 3K.

Terry

 

I have been unable to locate an EGR on this car. I just bought a good book
for it too and it is not anywhere to be found. This si my first time
working with Hondas. i've been a Ford man my whole life this on is the old
ladies. I want my SHO back so I need to fix this! I'm changing the therm
right now and have replaced the rotor and cleaned the points very well.
Thgis is just confusing to me. Thank for your input everybody. Hopefully I
can resolve it eventually.

 

If you have a manual transmission, then you have no EGR.

The EGR controls are in a big black box about 8"x6"x3" on the firewall next
to the wiper motor.

Terry mentions the ECU (the "computer"). He's had some interesting
experiences with flood-damaged ECUs but Honda ECUs are usually
exceptionally reliable. For now I would rule out the ECU.

That leaves everything else... :-/

Does the car seem to take a long time for the temperature gauge to get
close to the half-way mark?

 

Teggar wrote:

TeGGer® Apr 14, 4:42 pm show options

Terry mentions the ECU (the "computer"). He's had some interesting
experiences with flood-damaged ECUs but Honda ECUs are usually
exceptionally reliable. For now I would rule out the ECU.

That leaves everything else... :-/

Does the car seem to take a long time for the temperature gauge to get
close to the half-way mark?

--
TeGGeR®

-----------------------------------------
I ould be tempted to build a LED ignaitor tester.
You can't use a normal test lamp to test the drive to the
ignitor, but you can use a LED (light emitting diode) with a
~1000 Ohm 1/8W resistor in series. If the LED flickers
so fast that it almsot looks like is is constnaly on, during the
rough idle, then you might want to check the TDC sensor.

A simple oscilloscope will show the waveform and voltage level,
but very few of have one, or acess to one. A fairly decent DVM
with a 2V scale , 200mV is better, will show you if the TDC coil
is generating a voltage. I have seen voltages range from .5V to
over 1V. I don't know the actual spec, but 0.5V and lower would
lead me to think about replacing it.

Does it act funny even with the engine cold?
I saw a O2 sensor, before cat, casue this symptom in my sister's
Toyota. The shop wanted to repalce her ECM, but she was hesitant.
I disconeected teh O2 sensor and while the GPM dropped the engine
ran much better. She pikced up the OEM O2 sensor and dad and I
installed it can her car never gave any sign of trouble until the night
the stollan dump truck ran over wher it was aprked. My sis
s would only start hesitating when the eninge got warm and teh ECM
started "listening" to the O2 sensor.

I am really grasping at strwas, because ther are just oo many things
that could cause this. Many of them electrical or electronic.

Do you have AC?

The carbon cannister purge valve could cause a problem, I have
never heard of one failing, but a quick look in my manual suggests
that a constant leak there could really mess up the vacuum.

A Honda dealer mechanic told me that eh EACV (Electronic Air Control
Valve) could cause many odd drivibiltiy issues if it failed and leaked.

All I can offer is a whole lot of guesses.
Try to keep some notes on when the problem ocur.
As soon as you drive off from a cold start, only after it is warm,
Allways?
Such things might help to narrow it down.
If you just start chngning parts that you suspect have failed,
you could buy a newer car before you solve this problem.


I think Teggar has a link to a web page that show how to test the
ignitor.

One last thing. A friend has and ancient, 1976?, GM pickup. Pre modern
igniton. He ahad hesitation/stubling issues. During my odesy last fall
I bought a nifty little adjustablecalibrated spark gap that allow you
to
verify the spark volatage. His was very marginal. He replaced the
ignitoncoild and his problems went away. Advance auto carries this
gismo and it only costs about $6. A bargin. I is cheap enough that I
owudl consider buying one and see if the spark voltage is low/marginal
below 3K and
ok above that point.

Again kind of grasping at strwas.

Terry

 

Yes it does take a long time to get the temp up. I just changed the therm
from a 165 that was in there to the OEM spec 180. i have not taken a good
drive to check and see if the temp problem is resolved by this fix. As far
as the EGR, I still cannot locate the actuall vavle I am in the dark here
on the east coast right now so I cannot look for it or the box. I will
peek at this tom. Again guys, thank you very much for all your input.
Zak

 

OEM spec is ***194*** not 180!!!

180 would be an aftermarket thermostat.

Are you actually using an OEM thermostat? Or not?

 

Is the oxygen sensor the original?

For under $50 (and your own labor, which is minor for this), you can put in
a new OEM O2 sensor. Your symptoms are so severe I'd expect a Check engine
light, but maybe not always.

 

i have a 92 Accord that does the exact same thing = slow / no power on
acceleration up to ~2500rpm. plugs ok, wires ok, cap ok, rotor ok,
injectors ok, fuel filter ok, fuel pump ok, o2 sensor ok, thermostat ok /
temp normal. i don't know how to chk the ECU / ECM or the ignitor module
(where located?) or the distributor coil. any assistance would be GREATLY
appreciated