In Tank Fuel Pump

Help Support 7173Mustangs.com:

I decided to go ahead and put an electric fuel pump in my gas tank.  I know this has been discussed on the site before but there hasn't been any write ups.   I figure I would post this in the How To section for those who might be considering doing it.   I will start with prepping the tank and then move to the needed wiring.  

I found a couple of You Tube videos on doing our years cars and learned that the fuel pump and hanger assembly for an 85 to 93 Mustang will work.  After watching these videos and checking the specs one thing I noted was that these units are for fuel injection.   Since I have a carburetor I decided to piece mine together.  I do not plan on going to efi in the future.  If you do use one of the aftermarket ones for efi you will still need to make the height modifications as listed for it to fit.   

Several factors that I took into consideration was the pumps outlet size, the gph flow and the psi.  After doing some research I found out that there are 2 different model hangers for these years.  One has a 3/8” outlet and the other has a 5/16”.   I also wanted the pump to have the same size outlet as the hanger.

 One of the aftermarket manufacturers of these parts is Spectrum Premium (New Product Release (spectrapremium.com) .   I went to their website and was able to look up the hangers and the specs of their pumps.  I decided to go with the FG30B hanger. This hanger has the 3/8” outlet with 1/4” return. 

20210816_134335.jpg

For the pump I decided upon their SP1153.  This pump has a rating of 17 to 36 psi and a flow rate of 49.5 to 58.8 gph.   To figure you engines fuel rate go to the following to calculate. What size fuel pump do I need? (summitracing.com)   Also remember that these flow rates are based on WOT.   I would say SP1153 pump would work for any of our cars unless you are racing. 

20210816_160033.jpg

You will also need a new strainer.  The one that comes with the hanger will not work.  The pump requires a STR01 strainer.

20210816_160000.jpg

If you notice, these parts are listed on their website as now only being distributed in Canada.  I was able to find them all on eBay. 

To get started the first thing I did was to drain and remove the tank.  You can get the tank to siphon by pulling the fuel line off at the fuel pump.  I had a couple of 5 gallons gas cans I used to drain into.  After removing the tank I top vent and was able to get the rest of the gas out of the tank.  I then removed the sending unit and gave the tank a thorough cleaning. 

In my case when I remove my sending unit, I found out that the strainer was gone.  It had deteriorated over the years and was floating around in the tank in pieces.  See below pic.

20210815_133547.jpg

The are several modifications that need to be made to the hanger for it to fit.  The first is to move the hanger frame up on the main body by re-drilling new holes on each side of the outer portion of the frame.   Drill these as close to bottom as possible.  You will also need to bend the tabs out and flatten the bottom edge of this area so the frame sits flat against the main base.  There is also a tab sticking down at the bottom of the hanger that you need to cut off.

Below are the original screw placements.

Original location

20210816_134339.jpg

After modification.  You will still use the original thread holes on the main base of the unit. Here is the modified version.  Note that the tabs and the bottom edges of the frame need to be flatten.  The idea is to shorten the overall length of the hanger so you want to drill the holes vertical straight down.   Make sure to use some Loctite on the screws.

20210816_155914.jpg

You can see the tab on the below picture that needs to be removed.  You can either cut it off or bend it flat outward.

20210827_135441_resized.jpg

Since I was using the cars vent line as my return line and the gas cap is non venting, I needed to add a vent line.  I decided to add it to the hanger.  I did this by using a short piece of 3/16” brake line I picked up at the local parts store. 

The hanger has a 3rd line that stops at the top plate.  I drilled a 3/16” hole (which is the id of this line and also the od of the brake line) through the plate. I than epoxy the 3/16"  brake line in by inserting some epoxy into the tube and then inserted about 1” of the brake line in.  I than drilled a 3/32” hole through both tubes on the underside of the plate. 

Vent tube (2).jpg

3/16" hole drilled.

Drill vent tube.jpg

3/16" piece of brake line epoxy in. 

20210818_130511.jpg

3/32" vent hole drilled.  Make sure you can  feel air coming out of this by blowing on the end of the line.  You do not need to plug the bottom of the tube.

Inner vent hole (2).jpg

NOTE: This may not be needed if your car has a vented gas cap or if you run the return line and use the original fuel line outlet at the tank as your return in.  You can then use the hangers return inlet tube. You will need to drill a hole in the line right under the top plate for it to vent.  Do I have you confused yet!    Read on - it will become  clear.

I originally planned on using the 1/4” return line on the hanger as my return and that is why I added the additional vent line.  I ended up not being able to use it due to flow restriction so I could have used it as my vent line and not have added the additional line.

The placement of the unit in the tank is a little tricky.  You might want to do a few dry runs before you assemble everything to the hanger.  Our tanks have lands and valleys (high and lows rows) in the bottom.

 With the hanger in the tank slowly turn it until you feel it sitting in the bottom grove.  The original 1/4 “return line will be facing the front of the tank.   In the below picture the line on the right is the return line.  You can see that this is facing straight forward.  The center line is the additional vent line I added.  The line on the left is the outlet to the engine and is at an angle but will fit ok under the trunk.  I used a couple of zip ties to tighten thing up.

20210818_160117.jpg

20210818_160107.jpg

Unfortunately, I forgot to take a picture of the hanger and pump assembly together before I inserted it.  Below are a few pictures picture after it was inserted. 

Several things to note - When inserting the hanger it will be facing somewhat toward the left front side of the tank. Make sure that the strainer is facing parallel to the valley in the tank.  It needs to sit in this.   Also, the strainer needs to be bent up on one side when inserting the unit.  If you feel both ends of the strainer one side has less frame work to it. This is the side to bend upward as you insert the unit.   You will need to finagle a little to get the pump assembly inside the tank.  In the top of the tank there are two positioning slot for the old vent cap. I cut one of these wider to make it easier to insert the hanger.  

20210818_154753.jpg

20210818_154907.jpg

The final part of prepping the fuel tank is connecting wiring for power.  The pump terminals are not labeled.  With the pump connector at the six o’clock position facing you the terminal on the right side is the hot.  The connector that comes with the pump needs to be put together.  Take note of where this will plug into the hanger wiring.

  The right lead out of the pump needs to be connected to the red wire from the hanger.   Notice the difference width of the connectors.   Make sure that you have the right connectors match between the pump and hanger before inserting the pins into the connector for the pump.

20210827_135405_resized.jpg

The connector for the top of the tank is available at eBay and parts store.  I elected to make my own harness.

 I also decided to add some closed cell foam strips along the top of the tank as you can  see in some of the above pictures and to the holding straps to help isolate as much noise as possible.  I had this left over from the rear window installation.  I also had to get 1/2” longer tank strap bolts because this added depth to the tank.

20210819_111357.jpg

NOTE:

I notice that when I install the original sending unit that the float is right next to where the pump is and may actually be hitting it.  I bent my rod a little to the right toward the rear of the tank so it would clear it.  My fuel gauge seems to be working okay.    

I am going replace it in the next few weeks due to it is the original and looks kind of bad.  If I have any issues after I do I will update this post.

In the engine compartment I removed the old fuel pump and used a fuel pump cover plate. 

20210827_104626_resized.jpg

I also needed to decide where to place my bypass fuel regulator.   Since I was wanting to use the original vent line as my return, I decided to place it at the end of my fuel log.   This would give me the cleanest install.

20210820_115237.jpg

The bypass line hooks directly into the original vent line.

20210827_104646_resized.jpg

Wait until you have the electrical completed before making this connection at the tank.  You will want to run a little gas through the line into a bucket to flush the line out. I also put a fuel filter in the return line to ensure that the gas returning to the tank was clean. 

20210830_105648_resized.jpg

Not thinking about the bypass return flow rate, this placement ended up posing a problem due to the fact that I had the 5/16” vent line going into the 1/4” return on the hanger.  This caused back pressure and with having the regulator after the carburetor I was unable to adjust the psi below 9.  I then realized my mistake and took the return line at the tank and moved it over to the original 3/8” tank outlet and used that as the return inlet.  That relieved the backpressure and my psi dropped to about 4.  I was then able to adjusted the regulator to 7psi.

Please note that if you have the regulator before the carburetor, you will not have this problem and you can use the hangers 1/4" return.   In this set up you are restricting the pumps psi before the carburetor thus the flow rate back to the tank through the bypass doesn’t matter.  Either way is acceptable.

Regulator after the carb.  Fuel pressure is dependent on the bypass return flow and the regulator.  To small of a return line will create high pressure before regulator.

Regulator  After Carb.jpg

     [SIZE=11pt]Regulator before the carb.  [/SIZE]Fuel pressure at the carb is solely dependent on the regulator.

Regulator  BeforeCarb.jpg

I have my vent hose temporary attached to the old vent line facing the rear of the car.   I am making a bracket that I will mount the roll over vent shut off to.  This bracket will get mounted where my vent hose is located in the loop area on the flat flange there.  This is above the height of the gas tank filler.

20210830_105621_resized.jpg

Roll over vent valve.

Vent Adapter.jpg

Moving on to the electrical.   This part is pretty straight forward except you will want to add an inertia switch.  I have also added a manual rocker switch for anti-thief and also so I can have the ignition in the on position without the pump running.   I have installed the relay and inertia behind the driver side kick panel.

Here is a list of the items I used.  Most of these can be found at your local parts store.

Rocker switch for anti-theft and pump shut off (optional).   Inertia switch for pump shut off if in a collision.  One 12v relay.  Two in line fuses – one 10 amp and one 1 amp o what  your pump configuration may call for. 

Below is a schematic of my current wiring.

Final Wiring.png

I will be adding an oil pressure safety switch which will go in between the relay and the rocker switch.  I will be replacing the current single pole rocker with a single pole double throw rocker so I can run the pump if needed when the car is off and also use it as an anti-theft switch.  The following diagram will be my finish wiring with the new rocker switch and oil pressure switch.

Wiring with double throw.png

There are numerous other ways that you can wire the pump.  Various schematics are on the internet for your reference.

You will need to tie into a hot 12v source.  This can come from the battery or on the hot side of the starter relay.  I tied in to  the fuse block I added back when I did the alarm for the car.  You will also need to tie into a switch 12v source.  You can do  this  at the fuse box by finding a power source that only comes on when the  key is in the on/run position.  You will want to tap in before the fuse.  This added line will have it's own 1 amp fuse as shown in the above schematics. 

My 12v power source to pump.  Can also come direct from battery or off hot side of starter relay. 

20210802_154133 (2).jpg

12 V  30 amp relay. - you can use a 4 or 5 pin.   This will get tuck into the opening with the rest of the car connectors.

20210805_095754.jpg  

Inertia switch for collision or rollover.  This can be wired into the ignition side or power to the pump side of the relay provided it is rated to handle the pumps amperage.  I have mine wired in to the ignition side.

. 20210805_095733.jpg

Inertia switch mounted behind driver side kick panel.  Note the height that it is mounted.  This allows for easy reset without having to remove the panel.

20210805_103327.jpg

You can see the top the inertia switch just about flush with the top of the kick panel.  Easy to get to if you have to reset.

20210805_104231.jpg

Rocker on – off switch.  This allows me to turn the pump off with the ignition in the on position and also turn the pump on without the engine running.  Plus it is also used as an anti-theft switch.

20210805_110008.jpg

I ran the wiring to the pump through the rocker and into the trunk.  I ran it over to about the center and made my connection to the pump there.  Make sure to use a rubber grommet where you drill through the trunk.

20210802_154157 (2).jpg

20210819_152224.jpg

Cover wires back up with trunk mat.

20210806_115743.jpg

As mentioned earlier you will now want to run the pump without starting the car to flush out the old vent line.  Once you see clear gas flowing go ahead and attach a filter and attach to the return.  You are now ready to start the car.  

 I have been running this for a week now and have put a 150 miles on the car and it is working great.   If you have any questions send me a pm.  

Here is a short video on the sound of it if you can hear it.  It is quiet and can hardly be heard with the car off.


View attachment 1883757076_VideoFuelPumpRunning.mp4





































20210818_154907_resized.jpg

20210830_105814_resized.jpg

20210806_115748.jpg

20210818_154712.jpg

 
Last edited by a moderator:
Joined
May 19, 2021
Messages
421
Reaction score
137
Location
Fort Mohave, AZ & So Cal
My Car
73 Grande will undergo three phase build process. Phase 1 is to make roadworthy. Phase 2 is interior/exterior restoration. Phase 3 is ++ performance.
I just completed the pump and installed in tank. Thank you Kilgon for the excellent tutorial. I can’t wait to run it in a few months.
 
Top