91 Honda Civic tachometer problem(?)

Hi,

I have a 91 Civic with about 230k miles on it. Recently my tachometer
has been bouncing around a bit. Not dramatically, but enough for me to
know its abnormal (If I'm at 2000, occasionally it might drop down to
1800 and then jump right back). The car still seems to run fine and
there is no discernable change (in engine tone or anything like that)
when it happens.

Is this related to the distributor? I had changed it maybe 2 or 3
years ago. At that time it would make this faint (but audible)
clicking sound - especially if I would accelerate going up a hill. I
was told the bearings were bad at that time. Are these 2 problems
related and on another note, is it time to change my distributor yet
again? I had read somewhere about an ignitor problem? Are these the
same symptoms?

Thanks for any insight you can provide.

 

The distributor is the Achille's heel of early 90s Hondas.
Two sites that I respect both say that an erratic RPM can
indicate a failing igniter. See

http://www.marklamond.co.uk/howto/electrical/igniter/igniter
..htm

http://techauto.te.funpic.org/index.php?content=Ignition

For tests you can do to check the igniter, see the second
site above and also
http://www.tegger.com/hondafaq/startproblems.html#badigniter
..

I would do these tests first. I doubt the bearings on the
distributor housing are bad after only a few years.

Any idea how old the igniter is? The coil?

Is the distributor housing on your car OEM?

Of course it could be something else, but like I suggest at
the top, the distributor's parts should be a prime suspect.

Elle
Original owner, 1991 Civic LX, 172k miles, 2nd Distributor
Housing, yada

 

If the car still runs fine and there is no discernable change then the
problem is just the tach resistor, its connection or the instrument gauge.
How's the distributor, is hot by the touch?

 

Hi thanks for the information.

I will try these tests and get back to you.

I guess I should have mentioned that that exact same clicking sound
that I was told meant the distributor is going bad is happening again
now - so this goes back to my first question. I wouldn't think it
needs replacing either after only a couple years either, but what do I
know!

The distributor housing is OEM, as for the igniter and coil, I would
guess they are the original ones from 91 since I don't recall ever
replacing them - where are these 2 parts located and is it something
that a beginner could replace on their own?

Thanks again.

 

Last I checked, I wouldn't call it hot, but it was definately warm.
I will try checking it again after my next "trip".

Thanks for the help!

 

Hi thanks for all the info.

I would guess the igniter and coil are both the original ones from 91,
since I have no recollection of ever replacing them.

The distributor is OEM.

I will try these test and get back to you.

Thanks again!

 

I will try these tests and get back to you.

One of the tipoffs for bad distributor bearings is supposed
to be red dust in the distributor cap. I'd still be amazed
if the bearings had already gone bad again, but I hear you
about the noise sounding the same.

Another possibility:
Do you hear the clicking both when the engine is relatively
cool (after a morning start, for example) and after starting
when it is already warm?

If so, this implies the intake/exhaust valve lash is set a
little high but not necessarily out of spec.

When was the last time the valve lash was adjusted?

You did replace only the housing, right? On a car this old
the shop that replaced it might have figured you needed a
new igniter and coil at this age as well, for an extra $200
on top of the cost of the housing. To a customer not
particularly knowledgeable on the subject, that would be
easy to sell using the line, "You really need a whole new
distributor." Housing, coil, igniter, wha??

An advanced beginner with a decent set of wrenches and
sockets, a bit of patience, and a willingness to follow the
directions closely can definitely replace both of these on
his/her own. Do not overtighten the little distributor cap
bolts. Do not overtighten the bigger distributor housing
hold-down bolts. Both are just snug: Don't he-man them. (I
"He-Manned" the distributor cap bolts once and sheared the
thing off.) Preferably you'll use a torque wrench on the
hold-down bolts.

The first step to take is not in the manual and was a little
confusing to me the first time. Here it is: People in the
honda newsgroups advised marking the distributor and
camshaft housings so one does not have to re-check and
possibly adjust the timing. If you look at the three large
bolts that hold the housing in place, you'll see that the
flange through which they extend allows one to rotate the
whole housing assembly clockwise or counterclockwise. This
adjusts the ignition timing. I did not understand this until
I got the housing loose. Then it's too late. Yet it's not
catastrophic. Post if this step does not make sense. One can
actually kind of see part of the line I drew with a sharpie
market on my 91 Civic's housing at the bottom of
http://home.earthlink.net/~honda.lioness/id5.html . Look
just to the right of the top distributor housing hold-down
bolt. It's a little to the right of dead center of the
photo.

The second step is the only really tricky part:
Disconnecting the two electrical connectors to the
distributor. Figuring out which tab has to be pressed and
which way etc. always baffles me for 10 minutes or more. Go
slow. Have a tiny screwdriver to insert into the tab area to
mess with it until it comes free. It shouldn't take much
force at all.

Then follow the steps at www.autozone.com 's free online
manual for the 91 Civic. On the left at the autozone site,
click on "Repair Info," then "Vehicle Repair Guides." Click
on car year, make, and model, etc. Or use the steps given at
http://techauto.te.funpic.org/index.php?content=Ignition
(which does talk about making the mark I suggest above, only
using a razor blade).

See the autozone manual for directions for removing the
coil. I think removing the coil first makes removing the
igniter easier.

Here are directions for the igniter, or again see the
Autozone manual's directions.
http://www.marklamond.co.uk/howto/electrical/igniter/igniter
..htm

Tegger's unofficial FAQ site also has a lot of commentary on
both of these. It's worth reading at least once quickly,
taking notes as needed about removal, before you begin. See
http://www.tegger.com/hondafaq/faq.html#startprobtop .
Unfortunately the link for how to replace the igniter isn't
working at the moment. Tegger?

Good luck. Updates are welcome, since they help people in
the future.

Also, I would consider the other suggestions here (e.g.
Burt's re the Tach resistor) as well. Diagnosing over the
internet is hard but not impossible. Hang in there. These
vintage Hondas are amazing in their tenacity.