90 Civic Problem w/Relay, Fuel Pump, or ???

(Also posted to rec.autos.makers.honda)

HI All - new here, and I've learned a LOT by reading back articles for a
few days; thanks! I've got a problem with a '90 Civic Wagon AWD.

Symptoms - the car would not start when 'warm', and this started a
couple of months ago, as the temps started to climb here in SoCal. It
would run fine, then... after a quick stop, would refuse to start. I'd
wait a few minutes, and almost always, it would re-start and run fine. I
_never_ had any problems once the car was running - ran smooth, no
'missing', etc. SOMEtimes, the car would "try" to start - fire, and
vroom up for a split second, then die. But woyld then "really_ start
after a few minutes of waiting (cooling?)

The other day, I did a quick errand, came out to start the car, and all
it did was crank and crank... wouldn't start. THIS time, even after
_several_ attemps, I had to call for a ride. Of course, the car failed
AWAY from home (but only a mile or two) Still, I'm getting VERY tired of
going back and forth, diagnosing and 'testing' various theories!

After reading lots of great info (thanks!!) I assumed the Main Relay.
Finally found the sucker and took it out. Resoldered and tested the
relay per instructions in a Haynes manual, and it tests fine. All
switches seem to swith, as tested w/12V and continuity meter.

Plugged the relay back into the car - no go. Cranks like crazy, but will
NOT start/run.

So, I turn to the fuel pump. PREVIOUSLY, I _thought_ I could hear it
whirring. Now, it doesn't seem to 'whirr' when the key is turned on-??
Also, prior to this , there WAS the starting issue, but nothing else.

Questions for you Gurus and more experienced mechanics -

€ Can the Main Relay "test" OK, but still not work?

€ How often do Fuel Pumps fail & do I _really_ need to remove the tank
to get at it??

€ Can the fuel pump fail 'intermittenly'? (seems like it would either
work, or NOT work... this is - or was 'til the other day! - an
intermitten problem.

€ Could it be the Coil? There IS spark at the plugs, but I read
somewhere this isn't fool-proof.

So... do I buy a new Main Relay (I'd rather NOT spend the $60 -
especially if I don't need to!) Do I replace the fuel pump? Help!!

If I can't get this fixed soon, I ned to tow the sucker home to keep
diagnosing and testing... I fell like I'm close, but I'm hoping for some
wisdom & advice!

Thanks,
Tony

PS - If you don't mind, please send replies as e-mail AND posts to the
ng.. remember to remove spam blocker - thanks!

 

Not an expert, but I do have direct experience with the main relay (once
replaced), ignitor (replaced once at failure; a second time pre-emptively), and
the coil (replaced a few times, due to not using OEM).

Deduction leads me to believe the most likely causes of the no-start, in order,
are as follows:

1.
An improperly repaired main relay.

Here's what I get with my completely functional 1991 Civic LX's noises and dash
lights as I turn the key from position I to II. The top left, yellow-orange
"Check" light comes on and at the same time, I hear a dull humming noise from I
think the left rear of the car. I think that's the fuel pump motor. When the
"Check" light goes out, the humming stops.

So are you positive you're not getting this noise with the "Check" light?

How confident are you that you got the old solder off and properly re-soldered?
How confident are you of the electrical checks the Haynes manual prescribes?

Did you see the following sites when you did your Internet surfing on this
subject?

http://www3.telus.net/public/johnings/MainRelay.HTM (At the bottom, this
proposes an alternative cause to the symptoms of a failed main relay.)

http://www.markl.f9.co.uk/howto/electrical/main-relay/main-relay.htm

http://techauto.tripod.com/mainrelay.htm

http://tinyurl.com/4o2tl (what I think is a good, practical description of
re-soldering the relay)

Keep checking back, of course. John Ings et al. may be lurking and have more
specific advice on this one as well as the others.

2.
Failed ignitor (inside the distributor)
http://www.markl.f9.co.uk/howto/electrical/igniter/igniter.htm

3.
Failed distributor coil

I haven't seen many, if any, reports of early 90s honda fuel pump failures here,
so I personally wouldn't go there just yet. Of course you could groups.google
and see.

The three items above are much more common, from my reading and experience with
my 91 Civic.

 

Well... the lights are all like you describe. However, the humming noise
WAS there, and this morning, it wasn't. So now I'm back to suspecting
the Relay. Could a fuel pump work intermittently? Seems like it would or
wouldn't?? It NEVER was a problem once it started and was running.

I'm reasonably sure that the solder job is OK. (But the stopping of the
fuel pump 'humming' has me suspicious of my own work)

As for the testing, I'm pretty sure it's a proper test. Actually, I can
hear the "click" as I apply 12V to the prescribed contracts, then I get
continuity between the proper contacts (at least as described in the
Haynes manual). Between the "click" noise and the meter readings, I'm
_fairly_ sure it's OK. OTOH, I read another post (from a year or two
back) where someone had a relay that _tested_ OK, but did NOT function
properly IN the car. Not quite sure how THAT works, but I guess it
happened, and could certainly happen to ME. Anyone have any ideas on
this?? Could be heat, I suppose, but I tried it first thing this morning
and it was probably 70 or so (cool) in the car.

You folks are GREAT! I did find most of the links, but I'll re-read them
for good measure.

I did get a reply from John. Per his suggestion, I'm going to check the
fuel pump w/some help. Until today, the car was a couple of miles from
home & I was travelling back & forth trying to resolve the problem. I
finally gave up & had the car towed home where all of my tools and
'stuff' are (yes, yes, my wife TOLD me to just have it towed _right_
when it happened!)

Now that I have two people, it'll be easier to do the 'listening' test
for the pump, and I can have her turn the key while I check voltage at
the pump.

This really has me stumpped, but (with the great help I'm getting!) I'm
SURE I'll figure this out! And I'll certainly post back any
info/findings.

Thanks! And keep any ideas coming!!

Tony

--

 

Electrical connections (of various types) that are failing often work
intermittently for some time before full failure, as you're probably aware. Thus
I like the direction in which John Ings is sending you: Checking certain fuel
pump motor electrical wiring back to the source, etc.

Yes, I saw one post that said this, too.

I too am wondering about the mechanism here. The relay passes the bench test,
then fails the "in location" test?

If the problem is the relay, something is perhaps somehow different from bench
to car. (Perhaps not.)

It doesn't seem to take much to loosen/tighten those relay solder joints.
There's a couple of guys at the newsgroup who regularly say that, when one
suspects the relay's solder joints, one should hit the dash near the relay, and
the car will re-start. No one has ever challenged them on this.

Maybe just opening and closing the car door is having the same effect?

snip

Sounds like you're on the right track with checking all fuel pump motor etc.
electrical connections, even if this only eliminates a lot of things.

Ya know you can order that main relay from www.slhonda.com for $45 + shipping.
It's under "Electrical" etc. then "fuse box-relay horn." Part RZ-0063, as noted
in the center column of the parts listing.

Not to impugn your soldering ability. Nor others': I'm pretty convinced
re-soldering should work, based on the many reports at the newsgroup. I
completely replaced my 91 Civic's main relay in 1999, but I didn't know
re-soldering was an option then. I have had no hot weather or other
relay-related car problems since.

I'd be just a teensy bit inclined to definitely eliminate the main relay as the
problem, but that's more a comment on my lack of soldering experience...

Your misfortune will be someone else's (maybe my!) fortune some day soon.

Hang in there.

Re the towing: Ya, the spouses always know...

 

Hi - I was so interested to read your post, as my husband and I have both
had this problem with our Hondas. He has a 91 Civic LX and I have a 92 Civic
DX. Both of our cars run GREAT but if on a hot day we stop in between
errands, that's the end! Occasionally it seems like the cars start for a
second and then die. We have actually had mine towed several times, thinking
it was something really serious. We've replaced the battery and starter on
mine and the igniter and ignition switch on his, hoping this would fix
things but the problems persist! Elizabeth Angelo

 

Have you tried replacing the Main Relay? I'd bet that's it.

Frankly, after having mine towed home, I haven't done anything to it
(except be more frustrated!) for two days. In my case, the relay tests
fine on the bench, but the car doesn't start! Even after resting and
cooling off. :-( So, I'm thinking I'll just replace the relay for good
measure and seeing if that takes care of the problem. After all, ALL of
the research I've done (and it's been extensive at this point!) says
that even IF the relay is OK now, it's likely to go any moment. And for
$60 or so, maybe it's worth trying-?

I'll let you know how mine turns out!

Good Luck!
Tony

--

 

If it runs a little bit then stops, you might want to also check the
ignition switch.

 

I own a 1990 Civic, and here's what I do whenever mine does that (which it
still does, once in a blue moon) Turn the ignition switch completely off
and remove the key. Wait for about five seconds, then as quickly as you can
in one motion, put the key back in and turn the key all the way to the
"start" position immediately (DO NOT pause at the "on" position) Then,
theoretically, it should start up. If it doesn't, I'd say you probably do
have a bad fuel pump.

Jonathan