Which relay is bad when fuel pump doesn't work?

micky > wrote in
:


<snipped all of a very lengthy and confusingly-parsed post>


Browse through he
<http://www.tegger.com/hondafaq/startproblems.html#mainrelay>
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.



--
Tegger

On Mon, 22 Aug 2011 12:50:57 +0000 (UTC), Tegger >
wrote:

>micky > wrote in
:
>
>
><snipped all of a very lengthy and confusingly-parsed post>

Sorry.
>
>Browse through he
><http://www.tegger.com/hondafaq/startproblems.html#mainrelay>
>It should give you a pretty good idea how to check what you need to check.

This is a great page! I sent the url to her, for this and other
problems she might someday have.

>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.

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.

>Keep the original just in case you need to put it back.

Good idea.
>
>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.

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. .


>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.

I hope it doesn't come to that. I'm not changing her fuel pump.

Thanks a lot.

On Mon, 22 Aug 2011 12:50:57 +0000 (UTC), Tegger >
wrote:

>micky > wrote in
:
>
>
><snipped all of a very lengthy and confusingly-parsed post>
>
>
>Browse through he
><http://www.tegger.com/hondafaq/startproblems.html#mainrelay>
>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.

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. .

Thanks again.

micky > wrote in
:


>
> 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?



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!




> 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.




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.





>
>
> 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.



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
way.

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.




>
>
> 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. .
>



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.


--
Tegger

On Thu, 25 Aug 2011 18:13:53 +0000 (UTC), Tegger >
wrote:

>micky > wrote in
:
>
>
>>
>> 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?
>
>
>
>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!

Okay, to both instructions.
>
>
>
>> 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.
>
>
>
>
>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.

Okay.
>
>
>
>
>>
>>
>> 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.
>
>
>
>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
>way.
>
>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.

Maybe he tried to do that. Of course he had trouble. I will take the
easy way and unbolt it.

>
>
>
>>
>>
>> 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. .
>>
>
>
>
>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.

Yup.

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
next Sunday.

Thanks a lot.