Fuel System - 96 Caravan

My 96 caravan now runs out of gas when the tank is half full. I replaced
the fuel pump a few months ago (used unit), and has run fine for until now.
My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
the pump. This would effectively causing the pump air once the fuel level
was about half way down the pump body. However, I thought there might be
another cause. Does anyone know if problems with venting/evap system could
create the same symptom?

Did you have the fuel filter replaced when you had the fuel pump replaced? A
clogged filter can lead to failure of the fuel pump because the of the extra
pressure it has to exert to get fuel past a clogged fuel filter. The full tank
keeps the fuel pump cooled. When the tank gets half full, then not enough of
the fuel pump is submerged to keep it cool and then it fails. Filling the tank
restores its function. At least that was my experience (my repair guy actually
suggested replacing the fuel filter first, to see if that would correct the
problem, but it didn't; however, it's believed to have caused the failure in
the first place).
Carl

Mike C1 wrote:

> My 96 caravan now runs out of gas when the tank is half full. I replaced
> the fuel pump a few months ago (used unit), and has run fine for until now.
> My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
> the pump. This would effectively causing the pump air once the fuel level
> was about half way down the pump body. However, I thought there might be
> another cause. Does anyone know if problems with venting/evap system could
> create the same symptom?

Did you have the fuel filter replaced when you had the fuel pump replaced? A
clogged filter can lead to failure of the fuel pump because the of the extra
pressure it has to exert to get fuel past a clogged fuel filter. The full tank
keeps the fuel pump cooled. When the tank gets half full, then not enough of
the fuel pump is submerged to keep it cool and then it fails. Filling the tank
restores its function. At least that was my experience (my repair guy actually
suggested replacing the fuel filter first, to see if that would correct the
problem, but it didn't; however, it's believed to have caused the failure in
the first place).
Carl

Mike C1 wrote:

> My 96 caravan now runs out of gas when the tank is half full. I replaced
> the fuel pump a few months ago (used unit), and has run fine for until now.
> My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
> the pump. This would effectively causing the pump air once the fuel level
> was about half way down the pump body. However, I thought there might be
> another cause. Does anyone know if problems with venting/evap system could
> create the same symptom?

"Nomen Nescio" > wrote in message
...

> That's right Carl. But how's the poor sucker supposed to know when the
> filter is clogged? Mileage change intervals is a **** poor method because
> one load of Mexican gas can do more damage to your fuel filter than 12,000
> miles in the States.
>
> What's needed is some instrumentation on the fuel system. Like a pressure
> differential switch that senses pressure in vs pressure out of that
filter.

How about instead of an expensive complicated thing that is subjet to
breakage,
a simple 50 cent pressure relief valve built into the fuel pump itself.
When the output
pressure surpasses a predetermined amount, the valve opens and bleeds fuel
back into
the main tank.

That's such a good idea I am going to suggest it! Quick where's the phone
number.. oops, I forgot there already is one in there....

never mind.

Ted

"Nomen Nescio" > wrote in message
...

> That's right Carl. But how's the poor sucker supposed to know when the
> filter is clogged? Mileage change intervals is a **** poor method because
> one load of Mexican gas can do more damage to your fuel filter than 12,000
> miles in the States.
>
> What's needed is some instrumentation on the fuel system. Like a pressure
> differential switch that senses pressure in vs pressure out of that
filter.

How about instead of an expensive complicated thing that is subjet to
breakage,
a simple 50 cent pressure relief valve built into the fuel pump itself.
When the output
pressure surpasses a predetermined amount, the valve opens and bleeds fuel
back into
the main tank.

That's such a good idea I am going to suggest it! Quick where's the phone
number.. oops, I forgot there already is one in there....

never mind.

Ted

Did you have the fuel tank replaced under warranty? The first round of
plastic tanks in the '96 vans were known to warp and were readily replaced
by dealers.

One of the signs of warpage, unfortunately, are running out of gas because
you think it's still got some in it. The other is only being able to put 14
gallons in a tank that has run dry.

My 2 cents.

Bob


"Mike C1" > wrote in message
...
> My 96 caravan now runs out of gas when the tank is half full. I replaced
> the fuel pump a few months ago (used unit), and has run fine for until
> now.
> My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
> the pump. This would effectively causing the pump air once the fuel level
> was about half way down the pump body. However, I thought there might be
> another cause. Does anyone know if problems with venting/evap system
> could
> create the same symptom?
>
>

Did you have the fuel tank replaced under warranty? The first round of
plastic tanks in the '96 vans were known to warp and were readily replaced
by dealers.

One of the signs of warpage, unfortunately, are running out of gas because
you think it's still got some in it. The other is only being able to put 14
gallons in a tank that has run dry.

My 2 cents.

Bob


"Mike C1" > wrote in message
...
> My 96 caravan now runs out of gas when the tank is half full. I replaced
> the fuel pump a few months ago (used unit), and has run fine for until
> now.
> My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
> the pump. This would effectively causing the pump air once the fuel level
> was about half way down the pump body. However, I thought there might be
> another cause. Does anyone know if problems with venting/evap system
> could
> create the same symptom?
>
>

Thanks for the comments. I replaced fuel filter the other day, and ran out
again today. I then filled to full, the tank taking 6 gallons to reach
full. The tank is the original warped tank, but the bottom is not warped
inward enough to cause a run out after 6 gallons.

Does anyone know if the evap/purge system can possibly cause a vacuum in the
tank strong enough to counter the pump pressure? That is the only
explanation I can think of, other than a cracked/broken/disconnected inlet
tube on the fuel pump.

I just hate to drain and drop the tank again, and find out the problem is
elsewhere.

Mike C


"Mike C1" > wrote in message
...
> My 96 caravan now runs out of gas when the tank is half full. I replaced
> the fuel pump a few months ago (used unit), and has run fine for until
now.
> My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
> the pump. This would effectively causing the pump air once the fuel level
> was about half way down the pump body. However, I thought there might be
> another cause. Does anyone know if problems with venting/evap system
could
> create the same symptom?
>
>

Thanks for the comments. I replaced fuel filter the other day, and ran out
again today. I then filled to full, the tank taking 6 gallons to reach
full. The tank is the original warped tank, but the bottom is not warped
inward enough to cause a run out after 6 gallons.

Does anyone know if the evap/purge system can possibly cause a vacuum in the
tank strong enough to counter the pump pressure? That is the only
explanation I can think of, other than a cracked/broken/disconnected inlet
tube on the fuel pump.

I just hate to drain and drop the tank again, and find out the problem is
elsewhere.

Mike C


"Mike C1" > wrote in message
...
> My 96 caravan now runs out of gas when the tank is half full. I replaced
> the fuel pump a few months ago (used unit), and has run fine for until
now.
> My theory is that the fuel pickup elbow (with fuel sock) has fallen off of
> the pump. This would effectively causing the pump air once the fuel level
> was about half way down the pump body. However, I thought there might be
> another cause. Does anyone know if problems with venting/evap system
could
> create the same symptom?
>
>