Accord '91 sometimes won't start when it's hot

Hi group,

I have a honda Accord 91 LX and sometimes it just refuses to start in the
summer when it's hot and humid; and I'm in Texas so it's not very helpful.

The batterie is brand new so it's not the problem, when I try to start it I
hear the starter, but it just doesn't start. I've never had this problem
during cold weather, but when it's sitting in the sun in summer, especially
when it's humid (we had 2 inches of rain last night), sometimes it refuses
to start, like right now. What could be the problem? A guy at the garage
mentionned maybe a gaz relay thing or something like that. One day I had
this problem in houston and I just opened the doors for 10 minutes and I was
able to start after that. But today, no luck.

Thanks in advance for your ideas.

RAT

 

Classic symptoms of a failed main fuel relay. This is one of the weak points of
1990s Hondas.

You can re-solder the main relay (which I'm told is easy) or just buy a new one
(which I did in 1999, before I knew any better) for my 1991 Civic. A new one
costs around $40 online.

It's hard to get out on some cars but I've never heard of a DIYer failing in the
effort.

For more info, see any one or all of the following:

http://www3.telus.net/public/johnings/MainRelay.HTM

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

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

 

Caroline nailed it.

I have a '93 Civic DX that runs great. But for the past year it has been
driving me absolutely nuts with this hot staring problem. It would start
right up in the morning, but running errands became a crapshoot...short
trips between stores almost always resulted in starting problems. Also
parking in the sun might result in no start.

Do a Google search, something like "honda hot won't start" If the main
relay is your problem, you'll see people describing the same symptoms
you've experienced.

I finally found the same site Caroline listed:
http://www.markl.f9.co.uk/howto/electrical/main-relay/main-relay.htm

This was on thursday 6/24/04. The amazing thing was that when I pulled
out the main relay and looked at the soldering with a magnifying glass,
the *same* joint pictured on the web site was bad on my main relay!!! (It
*is* a pain to get the Main relay out; it's up under the dash near the
fuse box in my Civic).

If you can solder, the fix is easy. I used copper de-soldering braid from
Radio Shack and a Radio Shack 30Watt soldering iron.

I let the iron heat up, then put the desoldering braid next to the joint
and pressed on it with the iron. The solder melts and gets sucked up by
the braided copper. (I'll bet you could just strip some multistranded
copper wire and do the same thing)

I used some thin rosin core solder. Just touch the hot iron on one side
of the component lead coming up through the circuit board, and touch the
solder to the other side. As soon as the solder flows onto the pin, pull
the iron away. The result should look like the other (good) joints on the
board. I didn't redo every joint,only the 2 that looked marginal.

Bottom line? No problems since. I spent all day today going from place
to place, starting and restarting with complete confidence. I was parking
in the hot sun just for fun!!

Since it's intermitant, it's tough to diagnose. Mechanics unfamiliar with
this problem either admit they're stumped or try to convince you they've
fixed it by doing something else. If you are uncomfortable trying to fix
it yourself, make sure you let the garage know that you want them to test
the main relay before trying anything else.

Good luck!

jexter

 

thanks to you two, I am pretty sure that's my problem! By the way this line
from the page you suggest is so funny:

"This repair job can easily be performed with a 15 watt iron, and certainly
don't use a soldering gun"

RAT

 

its intermittant because its ok when cold, and seperates when hot.

if they take it out and check for continuity, itll probably test out OK.
its the heat thats the problem.

 

Great description.

As I've posted, I didn't re-solder the first time my main relay started acting
up but instead replaced. I have done a bit of soldering of electronics parts in
the past but was a little apprehensive about what all needed to be done to
remove the old solder on the main relay, should my second main relay fail again.
Your post clears the matter up nicely.

Ha ha...

 

By the way it happened again today, I'm totally convinced it's the relay,
when it doesn't start I don't hear the click, I was parked in the sun again.
Best quick fix I found so far: closing the driver's door really hard and
then start the car, it worked today. I'll get a new relay this week though!

RAT

 

I guess you missed the other thread... I just tell people to leave the
ignition in the II position... If you don't hear the pump run, SMACK the
left side of the dash (that's where the relay is). You'll hear the pump
run for two or three seconds, and off you go. Much simpler than
tow-trucks, or buying a bag of party ice to set on your dash :-( :-(

The cure is obviously to fix it, if you can get it out

'Curly'

 

Trust me I tried to smack the dash hard but no luck, for some reason the
door trick seemed to work better. I got my relay changed today for 97$ parts
and labor, not too bad considering I have pretty much zero tool to change it
myself. But it was cloudy and raining today, I won't know if the problem is
really fixed until I park in the hot texas sun again!

RAT