My next-door neighbor has a 2001 Honda Accord EX with a 4-cyl engine.
It wouldn't start, but did start when starting fluid was sprayed in
the air intake.
This indicates most likely the fuel pump or the fuel pump relay. The
dealer told her he has never had a bad fuel pump, but the relay can
overheat, and she should leave the doors open to let the interior cool
off. She tried that and the car started, less than 15 minutes later
The dealer said the relay wasn't with the other ones but under the
dash, and googling showed that the
However severl people, maybe even by pros, called it the fuel pump MSR
Main System Relay, and I think they are referring to the relay that
shuts down after a crash to prevent a fire. But her main system is
working, or the car would not start with the starter fluid.
So is the url below, an Airtex Access Relay 1r1455, the relay she
needs, or is there a separate fuel pump relay, that is different from
the fuel pump main system relay?
Did it start, but stall as soon as the key was released?
Did it crank, but show no sign of firing?
Can you hear the fuel pump run for two seconds when the key is first
turned to "II"?
Did the MIL illuminate as the starter was operated?
Not too sure of that. By 2001, Honda had seen enough cracked-solder
situations to have improved the PGM-FI Main Relay. These newer ones are
Your issue could simply mean weak spark. When were the HT ignition
components last changed? I'll bet you're running original OE parts, or
The dealer doesn't know.
Older traditional combined PGM-FI Main Relays did not "overheat", but
suffered from cracked solder. Letting the Relay cool down would
sometimes re-establish sufficient contact between the cracked parts to
Probably coincidence, in this case.
Very important questions: When the key is first turned to "II", does the
MIL illuminate for 15-20 seconds, then go off and stay off? And does it
remain off after the car is started? Or is it on all the time?
I think Honda uses the PGM-FI Main Relay for that purpose: Engine
stalls, fuel pump and injectors shut off. The engine must be turning for
the ECM to allow the fuel-pump and injectors to operate.
If your model is one of those new enough to have the traditional single
PGM-FI Main Relay split into two (which I'm not sure it is), then you
have one relay for the injectors and one for the fuel pump. They are
always installed together, in my limited late-model experience. And the
split kind are utterly reliable.
Don't go replacing possibly perfectly good OE parts with stupid and
alarmingly unreliable aftermarket. Diagnose the problem properly
instead. Start with the HT ignition components.
If you absolutely must replace the Relay, go to your nearest U-Pull
wrecking yard and get a proper OE Relay from a vehicle there, for likely
much less than the Airtex crap.
I haven't been in the car. She's never noticed. IIUC, it won't do
this a second time withina short period of time, so there was no point
in my listiening.
The mother-in-law? I don't know Honda lingo.
The spark was over 3/4 inch.
Yeah, I saw a webpage later where someone replaced the pump and things
This is in the relay itself, or a circuit board it is plugged into? >
I dunno. Which is good? Which is bad?
I can ask her. Maybe she noticed. .
Hmmm. By installed together, you mean next to each other
If the relay itself has bad solder connections, can I take it out and
Is it a mechanical relay with an armature and contract points, or a
I'm trying to diagnose it. The spark is good, but when I sprayed
starter fluid in, it ran. It stopped running a few seconds later,
when it ran out of starter fluid I think. I did this twice, same
result. So I think it's in the fuel system.
That much time, driving around the county in the heat, I won't spend
for her. I'm especially busy myself now., and she's just a
neighbor. Last I talked to her she seemed resigned to paying 200
at the dealer, even though she works 3 jobs to make ends meet. Well
maybe it's 1 job in the school year and 2 jobs in the summer, I' not
sure. I think she would go to a junk yard where they took it out
for her -- would you trust that that was an oriiginal honda part?
Are they marked as Honda parts? Maybe he won't want to pull the part
until she gets there, in case she doesn't show up, so she would follow
him to the car anyhow, and watch.
I also found, for 70 dollars, at autozone,
These should be good enough, right? And a lot less than 200.
<snipped all of a very lengthy and confusingly-parsed post>
Browse through here:
It should give you a pretty good idea how to check what you need to check.
If you want to buy an aftermarket Main Relay and take a chance on that, go
right ahead. They're all crappy, so it doesn't matter which one you buy.
Keep the original just in case you need to put it back.
The key to diagnosing the Main Relay consists of two things:
1) the behavior of the MIL (AKA "Check Engine Light"), and
2) fuel pump operation during the key-on sequence.
It is critical to pause the key at each station of the ignition switch and
observe the EXACT behavior that occurs at each position. You must listen
carefully for the correct clicks, and for fuel-pump operation (hum or
whine) at the correct times.
To diagnose the fuel pump itself: feed battery voltage directly to it using
a jumper wire. It should run continously as long as power is applied. If it
runs continously, then it is, itself, fine. Although its power feed through
the Main Relay may still be suspect.
This is a great page! I sent the url to her, for this and other
problems she might someday have.
She's also getting advice from someone else, who said aftermarket
relays would be cheaper, so I looked into it for her. I'm surprised
to hear they're so bad.
I didnt' try to get the price on a real Honda part, because I figure
dealer stock is usually not online.
Lookkng at your diagrrams on your webpage, I see why I was confused.
It's called a relay, but it's really at least two relays in sequence.
The first relay must work or the car wouldn't run with ether. The
second relay must be intermittent so sometimes the car doesn't start.
But I'll listen for the clicks too, and the check engine light. I
haven't sat in the car yet, and she's out now, along with her car. .
I hope it doesn't come to that. I'm not changing her fuel pump. :)
Thanks a lot.
I sent copies of your posts to my neighbor, and she wants me to
replace the relay with a Honda relay, which she's going to buy before
the weekend. (Her car has run okay since last Saturday.)
I'm concerned about two things.
1) In the 2001 EX is it obvious how to take off the panel in front of
the relay? Are there screws visible or is there some hidden latch?
Can you give me a clue where to start? Does it relate to the fuse
box? Her fuse box cover she took off -- it is big but on the side of
the dash and only visible when the driver's door is open.
2) I read one guy's story on the web who couldn't get the relay out of
its bracket. He'd already unplugged the connector and tested the new
relay, but couldn't get old relay out to do a nice looking job. The
one in the pictures from your webpage bolted on, but if this 2000 EX
is one that clips on, is there a trick to getting it out.
If this were my own car, I'd just keep at these things or die trying,
but I don't want her thinking half-way through shat she made a mistake
in letting me do this. Even if I finish it an hour or two later and
it's perfect. .
There are usually screws plus hidden plastic-clips similar to those in
the Web page I referenced.
You need to tug gently to see where the clips are, then apply pulling
force as close to the clips as you can.
Be certain to get ALL the screws! Some may not be in obvious locations!
The location should be shown in one of the sequences I show on the Web
page I referenced.
If not, you'll know what the Relay looks like, so just keep looking
until you find it. You can cycle the key on-and-off to make the Relay
click, which will help you locate it.
A new OEM Relay will come with a metal clip. This clip is what bolts to
the car's interior. The clip can be removed from the Relay and
reinserted upside down for those applications where it needs to be that
If your aftermarket Relay comes without a clip (likely), you're meant to
re-use the clip on the Relay that's in the car right now.
Some people manage to remove the Relay from its clip without unbolting
the clip from the interior. I've never done that.
Take your time and use common sense. This is an easy job. I just hope
this fixes your issue, othewise it will just be time and money wasted.
Maybe he tried to do that. Of course he had trouble. I will take the
easy way and unbolt it.
We were schedul;ed for Sunday monring, but it looks like it will be
raining buckets then because of the hurricane. Even though we're
inland in Baltimore. She has 3 jobs and may not be free until the
Thanks a lot.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.