Honda Car Forum

Michael Pardee wrote:
> "Matt Ion" <soundy@moltenimage.com> wrote in message
> news:PXcFg.419370$Mn5.171051@pd7tw3no...
>> TeGGeR® wrote:
>>> Matt Ion <soundy@moltenimage.com> wrote in
>>> news:v3REg.410737$iF6.53449@pd7tw2no:
>>>> TeGGeR® wrote:
>>>>
>>>>> Matt Ion <soundy@moltenimage.com> wrote in
>>>>> news:vINEg.420523$IK3.280117@pd7tw1no:
>>>>>
>>>>>
>>>>>
>>>>>> He's GOT a Haynes manual for this thing, which he can't find... i'm
>>>>>> SO much more useful with a good wiring schematic in front of me
>>>>>>
>>>>>
>>>>> Click Auto Repair Reference Center from the menu at left.
>>>>> Navigate to your car. There are wiring diagrams.
>>>> Sweet, thanks!
>>>>
>>>> Meanwhile... he's determined there's no power to the injectors. Ground
>>>> is good, but no signal into them. Waiting to see if he'll actually
>>>> bother to check the ECM codes (I sent him the link from your FAQ).
>>>>
>>>
>>>
>>>
>>> Power to the injectors is from the line that comes from Terminal 7 of the
>>> Main Relay. The fuel pump and the injectors receive power from the same
>>> basic source, so the trouble is probably a disconnected wire between the
>>> Main Relay and the injector harness.
>> Well, I actually got my hands on the car this afternoon and, with the help
>> of the schematic (you ARE the man!), I think I found the source of the
>> problem: the fuel pump is for some reason sinking TONS of current and
>> causing the voltage throughout the car to drop excessively.
>>
>> Specifically: checking voltage at the injectors, I get only about 8.5V
>> while they're activated, and closer to 5.5V when cranking. Voltage *at
>> the battery* drops from about 12V to just barely over 8V for a few seconds
>> as soon as the key is switched to Ignition, then jumps back up to 12V,
>> nicely coinciding with the brief time the main relay switches on the pump
>> and injectors. Connecting jumper cables to my running car, thus providing
>> 14V to the system, allowed the car to ALMOST start as system voltage
>> dropped to about 9.5V with ignition on, and 8.5V while cranking - it tried
>> to catch a few times, but just couldn't quite fire up.
>>
>> After a little more tracing, I ruled out the injectors and internal wiring
>> problems... looking at the schematic, there are only three things on that
>> circuit - the two injectors and the fuel pump - so I figured either there
>> was a "near-short" somewhere in its wire (a dead short would have blown
>> the fuse), or the pump was having issues... as it turned out, unplugging
>> the pump lead got rid of the strange voltage drop.
>>
>> So I'm thinking the pump probably has bad bearings or sleeves, or is badly
>> gummed up, or in some other way is being prevented from turning freely,
>> and thus is drawing excessive current, enough to drop the system voltage
>> too low to operate the ECM and/or injectors, but not enough to pop the
>> related fuse.
>>
>> Lordco was closed by this time, so my buddy's gonna pick up a new fuel
>> pump tomorrow... but he'll be installing it on his own, as I'll be down at
>> the football game!
>>
>> Hopefully that takes care of things... I'll let you know!
>
> Say... you don't have a bunch of voltage between the engine block and the
> chassis, do you? I'm just wondering how the fuel pump can drop the voltage
> so much without blowing the fuse.
>
> Mike
>
>
likewise....

"jim beam" <nospam@example.net> wrote in message news:ucOdnS2fp94JInjZnZ2dnUVZ_sOdnZ2d@speakeasy.ne t...
> Michael Pardee wrote:
> > "Matt Ion" <soundy@moltenimage.com> wrote in message news:PXcFg.419370$Mn5.171051@pd7tw3no...

> >> Well, I actually got my hands on the car this afternoon and, with the help
> >> of the schematic (you ARE the man!), I think I found the source of the
> >> problem: the fuel pump is for some reason sinking TONS of current and
> >> causing the voltage throughout the car to drop excessively.
> >>
> >> Specifically: checking voltage at the injectors, I get only about 8.5V
> >> while they're activated, and closer to 5.5V when cranking. Voltage *at
> >> the battery* drops from about 12V to just barely over 8V for a few seconds
> >> as soon as the key is switched to Ignition, then jumps back up to 12V,
> >> nicely coinciding with the brief time the main relay switches on the pump
> >> and injectors. Connecting jumper cables to my running car, thus providing
> >> 14V to the system, allowed the car to ALMOST start as system voltage
> >> dropped to about 9.5V with ignition on, and 8.5V while cranking - it tried
> >> to catch a few times, but just couldn't quite fire up.
> >>
> >> After a little more tracing, I ruled out the injectors and internal wiring
> >> problems... looking at the schematic, there are only three things on that
> >> circuit - the two injectors and the fuel pump - so I figured either there
> >> was a "near-short" somewhere in its wire (a dead short would have blown
> >> the fuse), or the pump was having issues... as it turned out, unplugging
> >> the pump lead got rid of the strange voltage drop.
> >>
> >> So I'm thinking the pump probably has bad bearings or sleeves, or is badly
> >> gummed up, or in some other way is being prevented from turning freely,
> >> and thus is drawing excessive current, enough to drop the system voltage
> >> too low to operate the ECM and/or injectors, but not enough to pop the
> >> related fuse.
> >>
> >> Lordco was closed by this time, so my buddy's gonna pick up a new fuel
> >> pump tomorrow... but he'll be installing it on his own, as I'll be down at
> >> the football game!
> >>
> >> Hopefully that takes care of things... I'll let you know!
> >
> > Say... you don't have a bunch of voltage between the engine block and the
> > chassis, do you? I'm just wondering how the fuel pump can drop the voltage
> > so much without blowing the fuse.
> >
> > Mike
> >
> >
> likewise....

I'm wondering the same thing...

If the pump is providing adequate pressure and has worked fine before then
what happens to the voltage if the fan blower is on max after the pump turns off?

Michael Pardee wrote:
> "Matt Ion" <soundy@moltenimage.com> wrote in message
> news:PXcFg.419370$Mn5.171051@pd7tw3no...
>
>>TeGGeR® wrote:
>>
>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>news:v3REg.410737$iF6.53449@pd7tw2no:
>>>
>>>>TeGGeR® wrote:
>>>>
>>>>
>>>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>>>news:vINEg.420523$IK3.280117@pd7tw1no:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>He's GOT a Haynes manual for this thing, which he can't find... i'm
>>>>>>SO much more useful with a good wiring schematic in front of me
>>>>>>
>>>>>
>>>>>
>>>>>Click Auto Repair Reference Center from the menu at left.
>>>>>Navigate to your car. There are wiring diagrams.
>>>>
>>>>Sweet, thanks!
>>>>
>>>>Meanwhile... he's determined there's no power to the injectors. Ground
>>>>is good, but no signal into them. Waiting to see if he'll actually
>>>>bother to check the ECM codes (I sent him the link from your FAQ).
>>>>
>>>
>>>
>>>
>>>
>>>Power to the injectors is from the line that comes from Terminal 7 of the
>>>Main Relay. The fuel pump and the injectors receive power from the same
>>>basic source, so the trouble is probably a disconnected wire between the
>>>Main Relay and the injector harness.
>>
>>Well, I actually got my hands on the car this afternoon and, with the help
>>of the schematic (you ARE the man!), I think I found the source of the
>>problem: the fuel pump is for some reason sinking TONS of current and
>>causing the voltage throughout the car to drop excessively.
>>
>>Specifically: checking voltage at the injectors, I get only about 8.5V
>>while they're activated, and closer to 5.5V when cranking. Voltage *at
>>the battery* drops from about 12V to just barely over 8V for a few seconds
>>as soon as the key is switched to Ignition, then jumps back up to 12V,
>>nicely coinciding with the brief time the main relay switches on the pump
>>and injectors. Connecting jumper cables to my running car, thus providing
>>14V to the system, allowed the car to ALMOST start as system voltage
>>dropped to about 9.5V with ignition on, and 8.5V while cranking - it tried
>>to catch a few times, but just couldn't quite fire up.
>>
>>After a little more tracing, I ruled out the injectors and internal wiring
>>problems... looking at the schematic, there are only three things on that
>>circuit - the two injectors and the fuel pump - so I figured either there
>>was a "near-short" somewhere in its wire (a dead short would have blown
>>the fuse), or the pump was having issues... as it turned out, unplugging
>>the pump lead got rid of the strange voltage drop.
>>
>>So I'm thinking the pump probably has bad bearings or sleeves, or is badly
>>gummed up, or in some other way is being prevented from turning freely,
>>and thus is drawing excessive current, enough to drop the system voltage
>>too low to operate the ECM and/or injectors, but not enough to pop the
>>related fuse.
>>
>>Lordco was closed by this time, so my buddy's gonna pick up a new fuel
>>pump tomorrow... but he'll be installing it on his own, as I'll be down at
>>the football game!
>>
>>Hopefully that takes care of things... I'll let you know!
>
>
> Say... you don't have a bunch of voltage between the engine block and the
> chassis, do you? I'm just wondering how the fuel pump can drop the voltage
> so much without blowing the fuse.

I've wondered that as well... I figure it's probably pretty marginal. Thing is,
the pump is normally on for only a couple seconds until you start cranking, at
which point the voltage drops a lot more because of the starter.

All major grounds are checked and solid - at first there was no standard ground
wire from the battery to the block, so we use a set of jumper cables, both from
the negative terminal, one to the block, one to the body.

Burt wrote:
> "jim beam" <nospam@example.net> wrote in message news:ucOdnS2fp94JInjZnZ2dnUVZ_sOdnZ2d@speakeasy.ne t...
>
>>Michael Pardee wrote:
>>
>>>"Matt Ion" <soundy@moltenimage.com> wrote in message news:PXcFg.419370$Mn5.171051@pd7tw3no...
>
>
>>>>Well, I actually got my hands on the car this afternoon and, with the help
>>>>of the schematic (you ARE the man!), I think I found the source of the
>>>>problem: the fuel pump is for some reason sinking TONS of current and
>>>>causing the voltage throughout the car to drop excessively.
>>>>
>>>>Specifically: checking voltage at the injectors, I get only about 8.5V
>>>>while they're activated, and closer to 5.5V when cranking. Voltage *at
>>>>the battery* drops from about 12V to just barely over 8V for a few seconds
>>>>as soon as the key is switched to Ignition, then jumps back up to 12V,
>>>>nicely coinciding with the brief time the main relay switches on the pump
>>>>and injectors. Connecting jumper cables to my running car, thus providing
>>>>14V to the system, allowed the car to ALMOST start as system voltage
>>>>dropped to about 9.5V with ignition on, and 8.5V while cranking - it tried
>>>>to catch a few times, but just couldn't quite fire up.
>>>>
>>>>After a little more tracing, I ruled out the injectors and internal wiring
>>>>problems... looking at the schematic, there are only three things on that
>>>>circuit - the two injectors and the fuel pump - so I figured either there
>>>>was a "near-short" somewhere in its wire (a dead short would have blown
>>>>the fuse), or the pump was having issues... as it turned out, unplugging
>>>>the pump lead got rid of the strange voltage drop.
>>>>
>>>>So I'm thinking the pump probably has bad bearings or sleeves, or is badly
>>>>gummed up, or in some other way is being prevented from turning freely,
>>>>and thus is drawing excessive current, enough to drop the system voltage
>>>>too low to operate the ECM and/or injectors, but not enough to pop the
>>>>related fuse.
>>>>
>>>>Lordco was closed by this time, so my buddy's gonna pick up a new fuel
>>>>pump tomorrow... but he'll be installing it on his own, as I'll be down at
>>>>the football game!
>>>>
>>>>Hopefully that takes care of things... I'll let you know!
>>>
>>>Say... you don't have a bunch of voltage between the engine block and the
>>>chassis, do you? I'm just wondering how the fuel pump can drop the voltage
>>>so much without blowing the fuse.
>>>
>>>Mike
>>>
>>>
>>
>>likewise....
>
>
> I'm wondering the same thing...
>
> If the pump is providing adequate pressure and has worked fine before then
> what happens to the voltage if the fan blower is on max after the pump turns off?

I don't know that it's providing ADEQUATE pressure... only that it's providing
SOME pressure.

Matt Ion wrote:
> Michael Pardee wrote:
>
>> "Matt Ion" <soundy@moltenimage.com> wrote in message
>> news:PXcFg.419370$Mn5.171051@pd7tw3no...
>>
>>> TeGGeR® wrote:
>>>
>>>> Matt Ion <soundy@moltenimage.com> wrote in
>>>> news:v3REg.410737$iF6.53449@pd7tw2no:
>>>>
>>>>> TeGGeR® wrote:
>>>>>
>>>>>
>>>>>> Matt Ion <soundy@moltenimage.com> wrote in
>>>>>> news:vINEg.420523$IK3.280117@pd7tw1no:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> He's GOT a Haynes manual for this thing, which he can't find... i'm
>>>>>>> SO much more useful with a good wiring schematic in front of me
>>>>>>>
>>>>>>
>>>>>>
>>>>>> Click Auto Repair Reference Center from the menu at left.
>>>>>> Navigate to your car. There are wiring diagrams.
>>>>>
>>>>>
>>>>> Sweet, thanks!
>>>>>
>>>>> Meanwhile... he's determined there's no power to the injectors. Ground
>>>>> is good, but no signal into them. Waiting to see if he'll actually
>>>>> bother to check the ECM codes (I sent him the link from your FAQ).
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Power to the injectors is from the line that comes from Terminal 7
>>>> of the Main Relay. The fuel pump and the injectors receive power
>>>> from the same basic source, so the trouble is probably a
>>>> disconnected wire between the Main Relay and the injector harness.
>>>
>>>
>>> Well, I actually got my hands on the car this afternoon and, with the
>>> help of the schematic (you ARE the man!), I think I found the source
>>> of the problem: the fuel pump is for some reason sinking TONS of
>>> current and causing the voltage throughout the car to drop excessively.
>>>
>>> Specifically: checking voltage at the injectors, I get only about
>>> 8.5V while they're activated, and closer to 5.5V when cranking.
>>> Voltage *at the battery* drops from about 12V to just barely over 8V
>>> for a few seconds as soon as the key is switched to Ignition, then
>>> jumps back up to 12V, nicely coinciding with the brief time the main
>>> relay switches on the pump and injectors. Connecting jumper cables to
>>> my running car, thus providing 14V to the system, allowed the car to
>>> ALMOST start as system voltage dropped to about 9.5V with ignition
>>> on, and 8.5V while cranking - it tried to catch a few times, but just
>>> couldn't quite fire up.
>>>
>>> After a little more tracing, I ruled out the injectors and internal
>>> wiring problems... looking at the schematic, there are only three
>>> things on that circuit - the two injectors and the fuel pump - so I
>>> figured either there was a "near-short" somewhere in its wire (a dead
>>> short would have blown the fuse), or the pump was having issues... as
>>> it turned out, unplugging the pump lead got rid of the strange
>>> voltage drop.
>>>
>>> So I'm thinking the pump probably has bad bearings or sleeves, or is
>>> badly gummed up, or in some other way is being prevented from turning
>>> freely, and thus is drawing excessive current, enough to drop the
>>> system voltage too low to operate the ECM and/or injectors, but not
>>> enough to pop the related fuse.
>>>
>>> Lordco was closed by this time, so my buddy's gonna pick up a new
>>> fuel pump tomorrow... but he'll be installing it on his own, as I'll
>>> be down at the football game!
>>>
>>> Hopefully that takes care of things... I'll let you know!
>>
>>
>>
>> Say... you don't have a bunch of voltage between the engine block and
>> the chassis, do you? I'm just wondering how the fuel pump can drop the
>> voltage so much without blowing the fuse.
>
>
> I've wondered that as well... I figure it's probably pretty marginal.
> Thing is, the pump is normally on for only a couple seconds until you
> start cranking, at which point the voltage drops a lot more because of
> the starter.
>
> All major grounds are checked and solid - at first there was no standard
> ground wire from the battery to the block, so we use a set of jumper
> cables, both from the negative terminal, one to the block, one to the body.

Oh, and... power readings at the injectors were tested with meter grounded to
battery, block, and body, at different times (whichever was most handy for that
particular instance).

Matt Ion <soundy@moltenimage.com> wrote in
news:PXcFg.419370$Mn5.171051@pd7tw3no:

> TeGGeR® wrote:
>> Matt Ion <soundy@moltenimage.com> wrote in
>> news:v3REg.410737$iF6.53449@pd7tw2no:
>>
>>
>>>TeGGeR® wrote:
>>>
>>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>>news:vINEg.420523$IK3.280117@pd7tw1no:
>>>>
>>>>
>>>>
>>>>
>>>>>He's GOT a Haynes manual for this thing, which he can't find... i'm
>>>>>SO much more useful with a good wiring schematic in front of me
>>>>>
>>>>
>>>>
>>>>Click Auto Repair Reference Center from the menu at left.
>>>>Navigate to your car. There are wiring diagrams.
>>>
>>>Sweet, thanks!
>>>
>>>Meanwhile... he's determined there's no power to the injectors.
>>>Ground is good, but no signal into them. Waiting to see if he'll
>>>actually bother to check the ECM codes (I sent him the link from your
>>>FAQ).
>>>
>>
>>
>>
>>
>> Power to the injectors is from the line that comes from Terminal 7 of
>> the Main Relay. The fuel pump and the injectors receive power from
>> the same basic source, so the trouble is probably a disconnected wire
>> between the Main Relay and the injector harness.
>
> Well, I actually got my hands on the car this afternoon and, with the
> help of the schematic (you ARE the man!), I think I found the source
> of the problem: the fuel pump is for some reason sinking TONS of
> current and causing the voltage throughout the car to drop
> excessively.
>
> Specifically: checking voltage at the injectors, I get only about 8.5V
> while they're activated, and closer to 5.5V when cranking. Voltage
> *at the battery* drops from about 12V to just barely over 8V for a few
> seconds as soon as the key is switched to Ignition, then jumps back up
> to 12V, nicely coinciding with the brief time the main relay switches
> on the pump and injectors. Connecting jumper cables to my running car,
> thus providing 14V to the system, allowed the car to ALMOST start as
> system voltage dropped to about 9.5V with ignition on, and 8.5V while
> cranking - it tried to catch a few times, but just couldn't quite fire
> up.
>
> After a little more tracing, I ruled out the injectors and internal
> wiring problems... looking at the schematic, there are only three
> things on that circuit - the two injectors and the fuel pump - so I
> figured either there was a "near-short" somewhere in its wire (a dead
> short would have blown the fuse), or the pump was having issues... as
> it turned out, unplugging the pump lead got rid of the strange voltage
> drop.
>
> So I'm thinking the pump probably has bad bearings or sleeves, or is
> badly gummed up, or in some other way is being prevented from turning
> freely, and thus is drawing excessive current, enough to drop the
> system voltage too low to operate the ECM and/or injectors, but not
> enough to pop the related fuse.
>
> Lordco was closed by this time, so my buddy's gonna pick up a new fuel
> pump tomorrow... but he'll be installing it on his own, as I'll be
> down at the football game!
>
> Hopefully that takes care of things... I'll let you know!
>

It might be just a clogged fuel pickup.

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik wrote:
> Matt Ion <soundy@moltenimage.com> wrote in
> news:PXcFg.419370$Mn5.171051@pd7tw3no:
>
>
>>TeGGeR® wrote:
>>
>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>news:v3REg.410737$iF6.53449@pd7tw2no:
>>>
>>>
>>>
>>>>TeGGeR® wrote:
>>>>
>>>>
>>>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>>>news:vINEg.420523$IK3.280117@pd7tw1no:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>He's GOT a Haynes manual for this thing, which he can't find... i'm
>>>>>>SO much more useful with a good wiring schematic in front of me
>>>>>>
>>>>>
>>>>>
>>>>>Click Auto Repair Reference Center from the menu at left.
>>>>>Navigate to your car. There are wiring diagrams.
>>>>
>>>>Sweet, thanks!
>>>>
>>>>Meanwhile... he's determined there's no power to the injectors.
>>>>Ground is good, but no signal into them. Waiting to see if he'll
>>>>actually bother to check the ECM codes (I sent him the link from your
>>>>FAQ).
>>>>
>>>
>>>
>>>
>>>
>>>Power to the injectors is from the line that comes from Terminal 7 of
>>>the Main Relay. The fuel pump and the injectors receive power from
>>>the same basic source, so the trouble is probably a disconnected wire
>>>between the Main Relay and the injector harness.
>>
>>Well, I actually got my hands on the car this afternoon and, with the
>>help of the schematic (you ARE the man!), I think I found the source
>>of the problem: the fuel pump is for some reason sinking TONS of
>>current and causing the voltage throughout the car to drop
>>excessively.
>>
>>Specifically: checking voltage at the injectors, I get only about 8.5V
>>while they're activated, and closer to 5.5V when cranking. Voltage
>>*at the battery* drops from about 12V to just barely over 8V for a few
>>seconds as soon as the key is switched to Ignition, then jumps back up
>>to 12V, nicely coinciding with the brief time the main relay switches
>>on the pump and injectors. Connecting jumper cables to my running car,
>>thus providing 14V to the system, allowed the car to ALMOST start as
>>system voltage dropped to about 9.5V with ignition on, and 8.5V while
>>cranking - it tried to catch a few times, but just couldn't quite fire
>>up.
>>
>>After a little more tracing, I ruled out the injectors and internal
>>wiring problems... looking at the schematic, there are only three
>>things on that circuit - the two injectors and the fuel pump - so I
>>figured either there was a "near-short" somewhere in its wire (a dead
>>short would have blown the fuse), or the pump was having issues... as
>>it turned out, unplugging the pump lead got rid of the strange voltage
>>drop.
>>
>>So I'm thinking the pump probably has bad bearings or sleeves, or is
>>badly gummed up, or in some other way is being prevented from turning
>>freely, and thus is drawing excessive current, enough to drop the
>>system voltage too low to operate the ECM and/or injectors, but not
>>enough to pop the related fuse.
>>
>>Lordco was closed by this time, so my buddy's gonna pick up a new fuel
>>pump tomorrow... but he'll be installing it on his own, as I'll be
>>down at the football game!
>>
>>Hopefully that takes care of things... I'll let you know!
>>
>
>
> It might be just a clogged fuel pickup.

If that was the case, there'd be no pressure on the pump and it would spin
freely; it wouldn't be drawing a ton of current.

Matt Ion <soundy@moltenimage.com> wrote in
news:ehoFg.422243$iF6.226183@pd7tw2no:

> Jim Yanik wrote:
>> Matt Ion <soundy@moltenimage.com> wrote in
>> news:PXcFg.419370$Mn5.171051@pd7tw3no:
>>
>>
>>>TeGGeR® wrote:
>>>
>>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>>news:v3REg.410737$iF6.53449@pd7tw2no:
>>>>
>>>>
>>>>
>>>>>TeGGeR® wrote:
>>>>>
>>>>>
>>>>>>Matt Ion <soundy@moltenimage.com> wrote in
>>>>>>news:vINEg.420523$IK3.280117@pd7tw1no:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>He's GOT a Haynes manual for this thing, which he can't find...
>>>>>>>i'm SO much more useful with a good wiring schematic in front of
>>>>>>>me
>>>>>>>
>>>>>>
>>>>>>
>>>>>>Click Auto Repair Reference Center from the menu at left.
>>>>>>Navigate to your car. There are wiring diagrams.
>>>>>
>>>>>Sweet, thanks!
>>>>>
>>>>>Meanwhile... he's determined there's no power to the injectors.
>>>>>Ground is good, but no signal into them. Waiting to see if he'll
>>>>>actually bother to check the ECM codes (I sent him the link from
>>>>>your FAQ).
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>>Power to the injectors is from the line that comes from Terminal 7
>>>>of the Main Relay. The fuel pump and the injectors receive power
>>>>from the same basic source, so the trouble is probably a
>>>>disconnected wire between the Main Relay and the injector harness.
>>>
>>>Well, I actually got my hands on the car this afternoon and, with the
>>>help of the schematic (you ARE the man!), I think I found the source
>>>of the problem: the fuel pump is for some reason sinking TONS of
>>>current and causing the voltage throughout the car to drop
>>>excessively.
>>>
>>>Specifically: checking voltage at the injectors, I get only about
>>>8.5V while they're activated, and closer to 5.5V when cranking.
>>>Voltage *at the battery* drops from about 12V to just barely over 8V
>>>for a few seconds as soon as the key is switched to Ignition, then
>>>jumps back up to 12V, nicely coinciding with the brief time the main
>>>relay switches on the pump and injectors. Connecting jumper cables to
>>>my running car, thus providing 14V to the system, allowed the car to
>>>ALMOST start as system voltage dropped to about 9.5V with ignition
>>>on, and 8.5V while cranking - it tried to catch a few times, but just
>>>couldn't quite fire up.
>>>
>>>After a little more tracing, I ruled out the injectors and internal
>>>wiring problems... looking at the schematic, there are only three
>>>things on that circuit - the two injectors and the fuel pump - so I
>>>figured either there was a "near-short" somewhere in its wire (a dead
>>>short would have blown the fuse), or the pump was having issues... as
>>>it turned out, unplugging the pump lead got rid of the strange
>>>voltage drop.
>>>
>>>So I'm thinking the pump probably has bad bearings or sleeves, or is
>>>badly gummed up, or in some other way is being prevented from turning
>>>freely, and thus is drawing excessive current, enough to drop the
>>>system voltage too low to operate the ECM and/or injectors, but not
>>>enough to pop the related fuse.
>>>
>>>Lordco was closed by this time, so my buddy's gonna pick up a new
>>>fuel pump tomorrow... but he'll be installing it on his own, as I'll
>>>be down at the football game!
>>>
>>>Hopefully that takes care of things... I'll let you know!
>>>
>>
>>
>> It might be just a clogged fuel pickup.
>
> If that was the case, there'd be no pressure on the pump and it would
> spin freely; it wouldn't be drawing a ton of current.
>

No,a pump trying to pull on a clogged line draws more current.
It spins freer under normal loads.Simple hydraulics.

--
Jim Yanik
jyanik
at
kua.net

Matt Ion <soundy@moltenimage.com> wrote in
news:PXcFg.419370$Mn5.171051@pd7tw3no:


>
> Hopefully that takes care of things... I'll let you know!



Matt, hold off until you know for sure that this is the issue. Posting
as-it-happens is an invitation to severe -- and likely inaccurate --
speculation.

Your thesis is intriguing. I await the synthesis, empirically arrived at,
of course...

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Matt Ion <soundy@moltenimage.com> wrote in
news:CtlFg.431985$IK3.362769@pd7tw1no:

>
> Oh, and... power readings at the injectors were tested with meter
> grounded to battery, block, and body, at different times (whichever
> was most handy for that particular instance).
>


Did ANYBODY attempt the particular procedure I prescribed? (To answer my
own question: evidently not.)

And does ANYBODY here EVER trim their posts?

--
TeGGeR®

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/