Fuel pump goblins
 

This isn't actually a honda problem, but I hope someone here can give me
some insight into what is happening & why.

I have a 93 Nissan pickup w/ electric fuel pump in gas tank. When it works,
it works fine.. until you shut engine off. It doesn't quit when engine is
running - regardless of how long it runs - 1 mile or 50. but after turning
engine off, fuel pump may or may not run. If it doesn't, it won't work
again until it sits a day or so.
Based on the schematic, I thought the problem was with the ECU to the fuel
pump relay, so I pulled the relay & jumped the circuit. It seemed to work
fine - started it several times over next couple of days - even let it run
& get up to operating temp, shut off & restarted fine.

Then drove it about 5 mi., and it wouldn't start afterward. Still wouldn't
start 3 hrs later, but started & drove it home about 20 hrs later. Turned
off & wouldn't start.

I guess I need to replace fuel pump, but I'm baffled as to why pump works
fine and continues to run as long as engine is running. It seems like a bad
pump would quit on the road instead of only when engine is turned off.

Re: Fuel pump goblins
 

jim L wrote:
> This isn't actually a honda problem, but I hope someone here can give me
> some insight into what is happening & why.
>
> I have a 93 Nissan pickup w/ electric fuel pump in gas tank. When it works,
> it works fine.. until you shut engine off. It doesn't quit when engine is
> running - regardless of how long it runs - 1 mile or 50. but after turning
> engine off, fuel pump may or may not run. If it doesn't, it won't work
> again until it sits a day or so.
> Based on the schematic, I thought the problem was with the ECU to the fuel
> pump relay, so I pulled the relay & jumped the circuit. It seemed to work
> fine - started it several times over next couple of days - even let it run
> & get up to operating temp, shut off & restarted fine.
>
> Then drove it about 5 mi., and it wouldn't start afterward. Still wouldn't
> start 3 hrs later, but started & drove it home about 20 hrs later. Turned
> off & wouldn't start.
>
> I guess I need to replace fuel pump, but I'm baffled as to why pump works
> fine and continues to run as long as engine is running. It seems like a bad
> pump would quit on the road instead of only when engine is turned off.
>
>

honda have been plagued by the solder on their main relay cracking. and
the symptoms are exactly the same as you describe. [if nissan use
mitsuba relays,] go to tegger.com, check out the resolution, then see if
it works for you.

Re: Fuel pump goblins
 

jim beam <spamvortex@bad.example.net> wrote in
news:SKidnSNLZsh3o33VnZ2dnUVZ_qLinZ2d@speakeasy.ne t:

> jim L wrote:
>> This isn't actually a honda problem, but I hope someone here can give
>> me some insight into what is happening & why.
>>
>> I have a 93 Nissan pickup w/ electric fuel pump in gas tank. When it
>> works, it works fine.. until you shut engine off. It doesn't quit
>> when engine is running - regardless of how long it runs - 1 mile or
>> 50. but after turning engine off, fuel pump may or may not run. If
>> it doesn't, it won't work again until it sits a day or so.
>> Based on the schematic, I thought the problem was with the ECU to the
>> fuel pump relay, so I pulled the relay & jumped the circuit. It
>> seemed to work fine - started it several times over next couple of
>> days - even let it run & get up to operating temp, shut off &
>> restarted fine.
>>
>> Then drove it about 5 mi., and it wouldn't start afterward. Still
>> wouldn't start 3 hrs later, but started & drove it home about 20 hrs
>> later. Turned off & wouldn't start.
>>
>> I guess I need to replace fuel pump, but I'm baffled as to why pump
>> works fine and continues to run as long as engine is running. It
>> seems like a bad pump would quit on the road instead of only when
>> engine is turned off.
>>
>>
>
> honda have been plagued by the solder on their main relay cracking.
> and the symptoms are exactly the same as you describe. [if nissan use
> mitsuba relays,] go to tegger.com, check out the resolution, then see
> if it works for you.
>

it's certainly a lot easier to replace or resolder the relay than to change
a fuel pump.

--
Jim Yanik
jyanik
at
kua.net

Re: Fuel pump goblins
 

"jim beam" <spamvortex@bad.example.net> wrote in message
news:SKidnSNLZsh3o33VnZ2dnUVZ_qLinZ2d@speakeasy.ne t...
> jim L wrote:
>> This isn't actually a honda problem, but I hope someone here can give me
>> some insight into what is happening & why.
>>
>> I have a 93 Nissan pickup w/ electric fuel pump in gas tank. When it
>> works, it works fine.. until you shut engine off. It doesn't quit when
>> engine is running - regardless of how long it runs - 1 mile or 50. but
>> after turning engine off, fuel pump may or may not run. If it doesn't,
>> it won't work again until it sits a day or so.
>> Based on the schematic, I thought the problem was with the ECU to the
>> fuel pump relay, so I pulled the relay & jumped the circuit. It seemed
>> to work fine - started it several times over next couple of days - even
>> let it run & get up to operating temp, shut off & restarted fine.
>>
>> Then drove it about 5 mi., and it wouldn't start afterward. Still
>> wouldn't start 3 hrs later, but started & drove it home about 20 hrs
>> later. Turned off & wouldn't start.
>>
>> I guess I need to replace fuel pump, but I'm baffled as to why pump works
>> fine and continues to run as long as engine is running. It seems like a
>> bad pump would quit on the road instead of only when engine is turned
>> off.
>>
>>
>
> honda have been plagued by the solder on their main relay cracking. and
> the symptoms are exactly the same as you describe. [if nissan use mitsuba
> relays,] go to tegger.com, check out the resolution, then see if it works
> for you.

Hi Jim - thanks for the reply
I read Tegger's entry on the mitsuba relays and Michael's description of
what happens with a Dry
Solder socket. It's enlightning - but not encouragong - looks like i'll
have to drop the tank and pull the fuel pump. My best gestimate is that the
bad solder connection is somewhere whithin the fuel pump assembly. I have
power to fuel pump with my jumped circuit - so main relay isn't the
problem. I was hoping for an easier fix - but at least knowing how it
could happen is positive.

Jim

Re: Fuel pump goblins
 

PS
is there anyone here who knows about elec fuel pumps? I may want to try &
fix this one. Autozone wants $199 for replacement, & Ebeay has some for
$70, but many say "all except US built King cab" which is what I have.
If I pull the pump I don't mind paying for replacement if it works but I
want it to work.

"jim L" <jtl57@bellsouth.net> wrote in message
news:raYDk.35289$IB6.6860@bignews8.bellsouth.net.. .
>
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:SKidnSNLZsh3o33VnZ2dnUVZ_qLinZ2d@speakeasy.ne t...
>> jim L wrote:
>>> This isn't actually a honda problem, but I hope someone here can give me
>>> some insight into what is happening & why.
>>>
>>> I have a 93 Nissan pickup w/ electric fuel pump in gas tank. When it
>>> works, it works fine.. until you shut engine off. It doesn't quit when
>>> engine is running - regardless of how long it runs - 1 mile or 50. but
>>> after turning engine off, fuel pump may or may not run. If it doesn't,
>>> it won't work again until it sits a day or so.
>>> Based on the schematic, I thought the problem was with the ECU to the
>>> fuel pump relay, so I pulled the relay & jumped the circuit. It seemed
>>> to work fine - started it several times over next couple of days -
>>> even let it run & get up to operating temp, shut off & restarted fine.
>>>
>>> Then drove it about 5 mi., and it wouldn't start afterward. Still
>>> wouldn't start 3 hrs later, but started & drove it home about 20 hrs
>>> later. Turned off & wouldn't start.
>>>
>>> I guess I need to replace fuel pump, but I'm baffled as to why pump
>>> works fine and continues to run as long as engine is running. It seems
>>> like a bad pump would quit on the road instead of only when engine is
>>> turned off.
>>>
>>>
>>
>> honda have been plagued by the solder on their main relay cracking. and
>> the symptoms are exactly the same as you describe. [if nissan use
>> mitsuba relays,] go to tegger.com, check out the resolution, then see if
>> it works for you.
>
> Hi Jim - thanks for the reply
> I read Tegger's entry on the mitsuba relays and Michael's description of
> what happens with a Dry
> Solder socket. It's enlightning - but not encouragong - looks like
> i'll have to drop the tank and pull the fuel pump. My best gestimate is
> that the bad solder connection is somewhere whithin the fuel pump
> assembly. I have power to fuel pump with my jumped circuit - so main
> relay isn't the problem. I was hoping for an easier fix - but at least
> knowing how it could happen is positive.
>
> Jim
>

Re: Fuel pump goblins
 

jim L wrote:
> "jim beam" <spamvortex@bad.example.net> wrote in message
> news:SKidnSNLZsh3o33VnZ2dnUVZ_qLinZ2d@speakeasy.ne t...
>> jim L wrote:
>>> This isn't actually a honda problem, but I hope someone here can give me
>>> some insight into what is happening & why.
>>>
>>> I have a 93 Nissan pickup w/ electric fuel pump in gas tank. When it
>>> works, it works fine.. until you shut engine off. It doesn't quit when
>>> engine is running - regardless of how long it runs - 1 mile or 50. but
>>> after turning engine off, fuel pump may or may not run. If it doesn't,
>>> it won't work again until it sits a day or so.
>>> Based on the schematic, I thought the problem was with the ECU to the
>>> fuel pump relay, so I pulled the relay & jumped the circuit. It seemed
>>> to work fine - started it several times over next couple of days - even
>>> let it run & get up to operating temp, shut off & restarted fine.
>>>
>>> Then drove it about 5 mi., and it wouldn't start afterward. Still
>>> wouldn't start 3 hrs later, but started & drove it home about 20 hrs
>>> later. Turned off & wouldn't start.
>>>
>>> I guess I need to replace fuel pump, but I'm baffled as to why pump works
>>> fine and continues to run as long as engine is running. It seems like a
>>> bad pump would quit on the road instead of only when engine is turned
>>> off.
>>>
>>>
>> honda have been plagued by the solder on their main relay cracking. and
>> the symptoms are exactly the same as you describe. [if nissan use mitsuba
>> relays,] go to tegger.com, check out the resolution, then see if it works
>> for you.
>
> Hi Jim - thanks for the reply
> I read Tegger's entry on the mitsuba relays and Michael's description of
> what happens with a Dry
> Solder socket. It's enlightning - but not encouragong - looks like i'll
> have to drop the tank and pull the fuel pump. My best gestimate is that the
> bad solder connection is somewhere whithin the fuel pump assembly. I have
> power to fuel pump with my jumped circuit - so main relay isn't the
> problem.

regardless, you need to methodical about this and eliminate known
failure points. start with the relay and then test the wiring - both
sides. you should be able to pull that without dropping the tank.

fyi, although you probably know this, it's ***EXTREMELY*** dangerous to
run fuel injection without main relay cutoff being active - what you
have with the jumped relay. crashed car, trapped inside, continuing to
pump gas onto a flaming engine... you'll take weeks to grow your hair back.



> I was hoping for an easier fix - but at least knowing how it
> could happen is positive.
>
> Jim
>
>