relocating a fuel pump

[21modelt]

I'm getting ready to install dual exhaust on my 84 cfi 5.0 liter an either I need to relocate my ext. fuel pump or install a newer in tank pump. Is it possible to relocate the ext. pump and if so can I get new fuel lines of any length since they snap on so to keep it very neat. If I install a new in tank pump then I still need to relocate my filter and I will need new lines for that also.

[21modelt]

I know this thread has been covered more than once but if I install a new pump in the tank do I go with an 86 year or ?

[bgriff]

I know this thread has been covered more than once but if I install a new pump in the tank do I go with an 86 year or ?

Get rid of the external pump setup and install the higher capacity fuel pumps for late 80's fuel injected mustangs. It is very straight forward with a few minor adjustments. A lot of people use the stock fuel lines.

[Quicksilver]

I did this to my 84 cfi 5.0. A pump from 87 to 93 swaps right in in place of the original in tank pump. I upgraded to a 190 litre pump as a stock pump is only 88 litres.

Also, I would recommend replacing the fuse able link (two foot long wire) to the in tank pump and also running a separate ground. Mine was fine for years without the wiring change but then one day the wires just got hot. I discovered this by accidentally touching the wires with the car running. I found the answer on an svo/turbo coupe website as a lot of people had experienced this. With this simple wire change, all wires are cold and all is well. This had also been affecting fuel pressure.

So, change pump, change two wires, relocate filter and have fun.
I also put some pictures of the wiring change on my build page.

[JACook]

The resistance wire was used up through at least '86, and only needs to be bypassed if you're using a higher
volume aftermarket replacement pump that draws more current. But that's not something I would do with a
CFI car. The stock Carter pump is already more than adequate, anything more is just making the fuel warmer
for no benefit.

Like the ballast resistor on an ignition coil, the job of that resistance wire is not to reduce voltage, but to limit
current. The resistance wire is there to keep the pump from being what gets hot when something goes wrong.

[Quicksilver]

The resistance wire was used up through at least '86, and only needs to be bypassed if you're using a higher
volume aftermarket replacement pump that draws more current. But that's not something I would do with a
CFI car. The stock Carter pump is already more than adequate, anything more is just making the fuel warmer
for no benefit.

Like the ballast resistor on an ignition coil, the job of that resistance wire is not to reduce voltage, but to limit
current. The resistance wire is there to keep the pump from being what gets hot when something goes wrong.

Jeff, good point.
Mine was originally changed when I had a stock cfi motor. I wanted to go to duals.
I did go with the 190 litre Motorsport pump and had no issues for years.

My issue came 15 years after an efi and roller motor conversion.
My issue came when I had a bad fuel pressure regulator and had high (70psi) fuel pressure.
After installing a new regulator, I got it down to 50 psi.
After changing the wire and grounding the pump, I'm at 39 psi.
Hopefully I'll have no issues in the future.
It was only with a rewired (92 harness), modified EFI roller motor that I had the wire get hot when using the high volume pump. But, everything had been fine for over 15 years.
So far so good.

[Mike Alan Grosvenor]

I am in the mix of installing dual exh on my '84 cfi, I am in need of relocating both the pump and filter from the passenger frame rails,
so if I'm hearing you correctly...
- There's a pump inside my fuel tank and outside?? Like a lift pump and then a psi/injection pump outside?
- So this pump from a '87-93, do I need the gas tank as well? What about the electrical connection?
- How did you connect the tubing from where the filter was located? Rubber hose and clamps?

On a side note, I heard I might have an issue with my brake line at the rear axle as well.. Any suggestions?

Thanks, and what a great fox you have
Mike

[JACook]

Yes, the CFI cars have a low-pressure lift pump in the tank, along with the high-pressure pump on the
chassis rail. The tank does not have to be changed to use the later high-pressure pump in the tank,
but you'll need a new pump hanger. Don't toss your original hanger and pump, some like to use those
for carb conversions.

You cannot use regular rubber fuel hose and clamps with the EFI system, but IF your tube ends have
proper barbs, you can use EFI-specific high pressure rubber hose, and EFI-specific screw clamps. (The
latter are not the same as regular worm clamps.) Or you can use the factory style high-pressure Nylon
lines, with the proper fittings.

Whichever you use, care must be taken to properly route and clamp the hose to the chassis, to prevent
chafing or other damage.

[Mike Alan Grosvenor]

Thanks, you said I will need to get a new pump hanger?? I'll check this out, to what your saying. Fuel filter should be able to be secured with a d-clamp, a really huge one.

[Mike Alan Grosvenor]

Thanks for the info, will there be a electrical connection change as well?

[JACook]

The high pressure pump doesn't fit the hanger inside the tank that's used with the low pressure lift pump.
Some listings you'll see might call it the fuel gauge sender, 'cause some people don't know that the pump
hanger and gauge sender are in two different places on the EFI Foxen.

The two different pump hangers have the same style connections.

[Mike Alan Grosvenor]

So, the CFI and EFI have the fuel gauge sending units in two different spots?

[JACook]

CFI and SEFI both have the sending units in the top center of the tank, well away from the fuel pump.

[JACook]

CFI and SEFI both have the sending units in the top center of the tank, well away from the fuel pump.
I only mention the sender, because I've seen people advertise the hangers as being the sender, which
they are not.

Here is what the '85-'93 pump hanger looks like -

[Mike Alan Grosvenor]

Thanks again, I'm away from my car on vacation trying to line everything up so there's NO surprises when I start in on it. Running into this problem with the attempt to install my dual exhaust was a speed bump I didn't foresee.
Thanks again!

[JACook]

I trust you already have plans to address the other speed bump, concerning the location of the rear brake
hose? That must also be relocated to the center of the rear end, as Ford did on the '85 and newer Mustangs
with dual exhaust.

[fgross2006]

Thanks, you said I will need to get a new pump hanger?? I'll check this out, to what your saying. Fuel filter should be able to be secured with a d-clamp, a really huge one.

Mike, I did a dual conversion on my 84 LX last summer. I gotta say you need to plan this well. Theres lots of bumps in the road to this one.

The stock bracket our cars came with for the fuel pump on the frame rail also held the fuel filter as well. In addition to converting to an 87 and up in tank fuel pump and fuel pump hanger, you will need the stock fuel filter bracket also from an 87 and up Fox body. I found one on ebay. The fuel filter must be relocated to just above the pumpkin of the rear end. My mechanic ran into issue moving the fuel filter because the stock fuel lines were all straight and he needed one that had a curve to enable rotating the filter bracket 90 degrees. You may have to find original fuel lines as well from an 87 -up.

Heres a pic of mine after being relocated.

Attachment 102233

You will need a dual hump crossmember. one from an 87 or an aftermarket one

[Mike Alan Grosvenor]

Thank you for the pix, that will help. Yeah I'm not crazy impressed with my lack of foresight on this project.

[Quicksilver]

Another option for relocating the fuel filter is to use the fuel filter mount from a Tempo or Topaz and mount it up above the axle.
When I relocated mine, I was trying to reuse the original mount. I looked at my Topaz and swapped the fuel filter mount into the Mustang...worked great.
The '87's and newer foxes were out yet.

[Mike Alan Grosvenor]

I noticed from your picture that you hadn't moved your brake line over for a dual exhaust, do you not have dual exhaust or did you do it another way?

[Mike Alan Grosvenor]

Another option for relocating the fuel filter is to use the fuel filter mount from a Tempo or Topaz and mount it up above the axle.
When I relocated mine, I was trying to reuse the original mount. I looked at my Topaz and swapped the fuel filter mount into the Mustang...worked great.
The '87's and newer foxes were out yet.

What at did you do with the old injection pump plug, the one on the frame rail?

[Mavereq]

I think I'm going to trace mine out and delete it, relay and all.

[Quicksilver]

What at did you do with the old injection pump plug, the one on the frame rail?

Mike, not sure I follow the question. I'll go take a look at the manuals and try to answer.
When I took the inline pump off and ran the in-tank pump, I got connectors and bridged the space with the proper plastic fuel injection hose, connectors, etc. from Ford. I later switched over to braided SS fuel lines.

[Mike Alan Grosvenor]

Mike, not sure I follow the question. I'll go take a look at the manuals and try to answer.
When I took the inline pump off and ran the in-tank pump, I got connectors and bridged the space with the proper plastic fuel injection hose, connectors, etc. from Ford. I later switched over to braided SS fuel lines.

u

Yeah the pump that is deleted from the frame rail, their is still the electrical connection going to no where now. Some one else on another thread said I have to short out that plug from under the Spare tire inside the car? But why would there be a connection there?

thanks for the response

[Quicksilver]

What I did was use the electrical connection at the tank for the in tank high volume pump and simply disconnect the inline pump. I capped off the wires.