Adding a backup fuel pump??? How?

[SOHCman]

After a recent fuel pump dilemma with our Taurus, I have theorizing adding a back up fuel pump incase the in-tank pump dies again. (Its a ford after all and this is a common problem)

Can a fuel pump be mounted inline? It would require the ability to flow when not in operation so the main pump can operate as normal.

If not, I was thinking of splicing a T into the main line with a check valve perhaps that would connect to a external fuel pump which fed from the tank. Kind of like a dual tank setup, but from the same tank. Also with a dash switch like a duel tank setup.

Most of this is determined by whether or not a fuel pump allows flow when off, and if they allow reverse flow at all (in leu of a check valve).

Discuss!

 

[Rand]

just buy a good fuel pump and it shouldnt be dying.


not a chinese or refurb

 

[artificialist]

Maybe you should go to a speed parts store that sells high performance in tank pumps. Take the old pump out of the fuel module and put the performance one in its place.

Test your electrical systems, some cars are prone to fuel system problems because a relay is going bad, or was poorly built.

Replace your fuel filter after the last pump dies. Pieces of the dead fuel pump almost always clog the filter.

 

[yonyon]

Before you get too far into this, see if your model has a return line and if is uses a fuel pump control module. If there's no return line or it uses a fuel pump control module you could be looking at a complex project. Keep a hammer and a remote start switch in the trunk instead. If it's just a pump that runs while the engine is running and there's a return line it'll be fairly simple.

 

[SOHCman]

The pump has failed while driving on the interstate, at city speed, and sometimes will turn but just wont start. No codes or anything, I believe its a return line system. If you sit for long enough perhaps to let it cool off(?), it will start again.

A hammer? I know that trick can work on a starter, but I cant exactly tap the fuel pump. Please explain.

 

[Chris142]

Originally Posted By: SOHCman

A hammer? I know that trick can work on a starter, but I cant exactly tap the fuel pump. Please explain.
Bang on the tank and it will rattle the Armature enough to get it spinning again. If I had a car with known Fuel pump problems I would consider cutting a hole in the bottom of the trunk or wherever the pump was for access.

Some cars come with an acess plate already.

 

[yonyon]

Originally Posted By: SOHCman
The pump has failed while driving on the interstate, at city speed, and sometimes will turn but just wont start. No codes or anything, I believe its a return line system. If you sit for long enough perhaps to let it cool off(?), it will start again.

A hammer? I know that trick can work on a starter, but I cant exactly tap the fuel pump. Please explain.


That hardly sounds like a typical fuel pump problem. If you're sure it's the pump and it's got a weird problem like that, why not just replace it and be done with it?

 

[The_Eric]

I agree with yonyon. Make sure the diagnosis is correct and use quality replacement parts and you're not likely to have a problem again for a very long time.

Also, always use a new inline fuel filter where applicable when installing a new fuel pump.

 

[meep]

i do not know of a FI fuel pump that will free-flow... the one's i have dismantled are all positive displacement, similar to some oil pumps.

some newer tanks put the pump in a canister that itself is fed by a jet pump, so the pump itself is always in full fuel until the tank is entirely exhausted. this setup would be harder to plumb with an external pump.

suggest highest quality oem style pump that you can find.

also suggest running a temporary test light to pump power so you can verify it's seeing power when it stalls. you'll want to verify that this is indeed the pump and not flaky relay or ecu.

 

[LeakySeals]

Originally Posted By: yonyon
Originally Posted By: SOHCman
The pump has failed while driving on the interstate, at city speed, and sometimes will turn but just wont start. No codes or anything, I believe its a return line system. If you sit for long enough perhaps to let it cool off(?), it will start again.

A hammer? I know that trick can work on a starter, but I cant exactly tap the fuel pump. Please explain.


That hardly sounds like a typical fuel pump problem. If you're sure it's the pump and it's got a weird problem like that, why not just replace it and be done with it?

What year? My ex wife had a brand new 06 escape she got rid of because the fuel pump failed 3 times in the 1st 30k. Each time left waiting for AAA dead on the side of the road. No warning, poof, dead with hardly any steering, barely any brakes coasting to the side of the road!

 

[mattd]

No need to re-engineer the car. Use a quality pump (OEM preferred) and you are unlikely to see recurring issues.

And to answer your question about "tapping the pump", he meant banging on the tank with a hammer to get it off the "dead" spot.

 

[mechtech2]

It can't be done.
MAYBE a system that can be switched over if one fails, but not two at once.
And how will you mount it in the tank anyway?
Get a good one and take your chances.
This is one reason I use Marvel Mystery Oil in the fuel. It helps lubricate fuel pumps. Many fuel pumps were designed when worse lubicating alcohol fuels were not even used.

 

[SOHCman]

Originally Posted By: mechtech2
It can't be done.
MAYBE a system that can be switched over if one fails, but not two at once.
And how will you mount it in the tank anyway?
Get a good one and take your chances.
This is one reason I use Marvel Mystery Oil in the fuel. It helps lubricate fuel pumps. Many fuel pumps were designed when worse lubicating alcohol fuels were not even used.


I use a synthetic tcw-3 oil for this very reason, at 1 oz per 5 gal, but even that couldn't prevent it from happening.

If there is no pump that will flow, then the idea is a bust. Unless you mount a "straw" with strainer type setup from the top of the tank, but I don't think its smart to mess with the tank like that unless there were a grommet plug or something to go through from the top of the tank.

 

[TFB1]

Originally Posted By: mechtech2
It can't be done.


Not so, my Marauder has two pumps plumbed/wired in parallel inside the tank(originally it had one) to feed the fuel demands of the supercharger, of course both run so is a different situation... This is on a returnless system so never say never...

1980s Fords often had a tank pump and another in line, the inline pump would run the vehicle if the tank pump failed... Still pumps don't fail all that often but do become intermittent(my failed pump would not start with any amount of banging on the tank, after a hr's rest it ran fine again)... No doubt could be done on a newer vehicle but pumps fail so seldom, I doubt it's worth the effort as a backup...

 

[yonyon]

If it's a return type system you can split the line, put a check valve on one side, and install a fuel pump inline on the other leg powered by a relay and manual switch. A pump intended for frame rail mount would be better suited as it won't overheat and fail from extended use as a pump intended for in-tank use will. I am assuming you plan to mount this outside the tank. Be sure the pump that you choose is rated for at least the pressure that your FI system requires. The check valve might not be readily available from the local auto parts store but any speed shop should be able to find something suitable. You could also use a solenoid valve (wired up in parallel with the backup pump) that's rated for the gasoline and pressures required. An outfit that services oil heat equipment should also have something suitable.

Modifying the fuel line should be pretty simple and straightforward if you're working with steel line. I would recommend using seamless stainless. If you're going in at a plastic line I know NAPA sells a kit for repairing plastic fuel lines so other stores should as well. It will cost more than working with steel lines. Whatever material you're working with be sure that it's securely mounted, won't chaff, and none of your mounting hardware will trap water or dirt against metal.

 

[mechtech2]

Originally Posted By: TFB1
Originally Posted By: mechtech2
It can't be done.


Not so, my Marauder has two pumps plumbed/wired in parallel inside the tank(originally it had one) to feed the fuel demands of the supercharger, of course both run so is a different situation... This is on a returnless system so never say never...

1980s Fords often had a tank pump and another in line, the inline pump would run the vehicle if the tank pump failed... Still pumps don't fail all that often but do become intermittent(my failed pump would not start with any amount of banging on the tank, after a hr's rest it ran fine again)... No doubt could be done on a newer vehicle but pumps fail so seldom, I doubt it's worth the effort as a backup...


You are absolutely right! Most anything can be done - and nice work getting yours up and running!
But your special needs are not what this civilian is trying to achieve in a normal bread and butter street car.
And if there was an accident, what about he repercussions and legalities if a fire occurred? An additional interial cut off system would have to be devised.

 

[yonyon]

Originally Posted By: mechtech2
Originally Posted By: TFB1
Originally Posted By: mechtech2
It can't be done.


Not so, my Marauder has two pumps plumbed/wired in parallel inside the tank(originally it had one) to feed the fuel demands of the supercharger, of course both run so is a different situation... This is on a returnless system so never say never...

1980s Fords often had a tank pump and another in line, the inline pump would run the vehicle if the tank pump failed... Still pumps don't fail all that often but do become intermittent(my failed pump would not start with any amount of banging on the tank, after a hr's rest it ran fine again)... No doubt could be done on a newer vehicle but pumps fail so seldom, I doubt it's worth the effort as a backup...


You are absolutely right! Most anything can be done - and nice work getting yours up and running!
But your special needs are not what this civilian is trying to achieve in a normal bread and butter street car.
And if there was an accident, what about he repercussions and legalities if a fire occurred? An additional interial cut off system would have to be devised.


Would that really be necessary? The vehicle already has an inertia shutoff switch. The backup pump could be wired so that it's fed 12V+ from a relay that gets its 12V+ from the existing inertia switch.

Even if it doesn't get done that way, is it really any issue as far as legalities go in the event of an accident? I'm not up on legal stuff, but I'm sure there a few here who might have at least some such knowledge.

Consider the case of a car crash with a mini spare in use: The car is being operated in diminished capacity due to the use of an emergency spare part which requires the driver use additional caution while driving. This mode of operation may cause an accident regardless of whether or not the operator exercises such due caution.

Now the case of the backup fuel pump that isn't wired through the inertia switch: The car is being operated in diminished capacity due to the use of an emergency spare part which requires the driver take additional safety measures after a collision, specifically turning off the ignition. This mode of operation will not cause an accident, but could possibly increase the severity of damages after one if the driver is incapacitated or fails to turn off the ignition for another reason.

Are these different in the eyes of the law?

 

[mechtech2]

The second pump would double the load on the system and wiring. A higher rated fuse or relay is not enough. Separate wiring would really be needed - separate circuits.

Really, for a common street car like you have, use some lube in the fuel, and just get a good pump.
Note that your new dual set up is likely to be MORE prone to problems!

 

[yonyon]

A good reliable pump is certainly the better choice, but how would a second pump be increasing the load on anything if the two don't run at the same time?