Has anyone?

[KANTANKRUS]

Replaced their internal fuel pump (abandon in place), for an external fuel pump? And if so, can you supply me with a link and or photos and descriptions.

 

Should I install a check valve, too!

[Warren Mohler]

If you do this mount as close to tank as possible, would not recommend drawing through existing pump, check valve may not be needed

[JustEmptyEveryPocket]

I swapped to an external pump. After the third time of pulling it, I got tired of dropping the fuel tank. Its been a while since I did this, and I didn't take pictures, but here is the gist of it:

1. Removed fuel pump in tank.

2. Bent brake line and attached in tank pickup using fuel rated hose.

3. Cut and spliced in a small fuel filter directly outside of tank. Something like THIS.

4. Removed original fuel filter and replaced with E2000 fuel pump. The location was ideal, and the new pump fits beautifully in this location. 

5. Ran all new wiring back to the pump. Ground directly from battery ground, power directly through a relay and from the battery, and the trigger spliced into the original truck's system. Thanks to Ohm for helping me figure it all out.

 

So the new pump functions exactly like the old one, but has better wiring and is MUCH easier to change. To be safe I also change the fuel filter at every oil change. Since it is smaller, I figure it will jam up faster. But I have been running this for ~1-2 years I think. No complaints besides the sound of the pump. I can't hear it at speeds above ~10mph, so its not really a big deal. However, in the summer, in stop and go traffic, it can be pretty miserable. But that is infrequent for me.

 

Anyways, from my perspective, I would recommend the mod. 

 

 

 

[KANTANKRUS]

Awesome reply!

[Dzimm]

On 12/31/2019 at 11:50 AM, JustEmptyEveryPocket said:

I swapped to an external pump. After the third time of pulling it, I got tired of dropping the fuel tank. Its been a while since I did this, and I didn't take pictures, but here is the gist of it:

1. Removed fuel pump in tank.

2. Bent brake line and attached in tank pickup using fuel rated hose.

3. Cut and spliced in a small fuel filter directly outside of tank. Something like THIS.

4. Removed original fuel filter and replaced with E2000 fuel pump. The location was ideal, and the new pump fits beautifully in this location. 

5. Ran all new wiring back to the pump. Ground directly from battery ground, power directly through a relay and from the battery, and the trigger spliced into the original truck's system. Thanks to Ohm for helping me figure it all out.

 

So the new pump functions exactly like the old one, but has better wiring and is MUCH easier to change. To be safe I also change the fuel filter at every oil change. Since it is smaller, I figure it will jam up faster. But I have been running this for ~1-2 years I think. No complaints besides the sound of the pump. I can't hear it at speeds above ~10mph, so its not really a big deal. However, in the summer, in stop and go traffic, it can be pretty miserable. But that is infrequent for me.

 

Anyways, from my perspective, I would recommend the mod. 

 

 

 

This would be good for a write-up!  Give it a few years and I think more people are going to need this info.

[Jeep Driver]

You guys are reinventing the wheel, again. 

 

These are still available new, OEM NOS,  I have mine. 

 

[Jeep Driver]

BTW, 

 

Tubing is 3/8 OD........look to something like a 70 Chevelle of Nova or Impalla for a sock. 

I searched some time back and I cannot remember which one.......but standard for GM. 

 

 

Edit: https://www.summitracing.com/parts/opg-ch28638?seid=srese1&gclid=CjwKCAiAo7HwBRBKEiwAvC_Q8ZqznwPm5z37amB1bnQsLofnXdZ5Vp6pESJJOKbgd_YOOGSf5_bT9xoCqcIQAvD_BwE

[DirtyComanche]

This is my opinion.

 

No normal external pump setup is reliable for a higher pressure FI vehicle.  The Ford style pump that everyone uses actually came in conjunction with an in tank "lift" pump that provided it with a positive head pressure.  When not used in this arrangement it is not reliable, and many people have proven this over the years by running it in a manner other than how the factory intended.

 

The only way to make this setup reliable is to use a pump that was really meant to be run externally and actually drawn fuel from a sump, which there isn't many of and they're really expensive, or to run a lift pump, which defeats the purpose of the external pump, or to run one that is below the sump of the fuel tank using a bottom feed pickup (as in drill a hole in the bottom of the tank to feed it), which will not package well in this chassis using the stock tank and therefore isn't really viable either.

 

All the racers that run external pumps, and actually want to finish the race, run dual pumps.  Life is measured in hours rather than thousands of miles.  The guys I gave a hand to with racing only ran a single pump, and it was replaced every race, and even then we still had a DNF due to a failed pump.

[Jeep Driver]

In my case- I have two problems to overcome. 

My current sender causes my Speedhut gauge to wander. I plugged in the new sender and gauge does not wander, old sender is worn out. This never happened with the stock fuel gauge, I'm assuming the Speedhut is far more sensitive than the stock gauge. 

Speedhut gauge if fully programmable, what sender I use is irrelevant. 

 

Secondly, I need 45psi with enough volume to feed a SBC. 

 

If I use only the stock tank and external pump- Aeromotive, I'll be looking at about $700 for pump and regulator. Beyond $1000 for the pump if I go brushless. 

Since I won't be driving over tree stumps......bottom of tank bulkhead fitting is not out the realm of solutions. 

 

Another possible solution, maybe most viable- https://www.summitracing.com/parts/hpf-49115/overview/

 

Since my bed will see nothing more than a couple of suit cases and a cooler.....spare tire and jack........under a tonneau cover.

I'm considering a fuel cell mounted behind the cab, modern in-tank pump and sender. 

Then use my existing tank as a secondary with the existing pump as a transfer pump to the fuel cell. This will also give me more than 30 gallons. 

Fittings, braided steel hose, regulator........I'll still be in the $1000 to $1200 neighborhood. 

 

 

You are right, whatever the solution, it's expensive. 

 

But you have to be prepared to leave the Tribe........I walked away long ago. 

 

 

 

[High2by]

10 hours ago, Jeep Driver said:

You guys are reinventing the wheel, again. 

 

These are still available new, OEM NOS,  I have mine. 

 

Where do you get one of these?

[Warren Mohler]

1 hour ago, High2by said:

11 hours ago, Jeep Driver said:

Where do you get one of these?

tried to copy and paste didn't work, SEE Ebay item # 392419963971 this a new ebay offer I just came across-trexautoparts111014

[Jeep Driver]

8 hours ago, High2by said:

Where do you get one of these?

https://www.ebay.com/itm/NOS-86-Jeep-Comanche-Fuel-Tank-sending-unit-assy-18-23-5-gallon-tank-52003652/232057535509?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

[High2by]

https://www.ebay.com/itm/NOS-86-Jeep-Comanche-Fuel-Tank-sending-unit-assy-18-23-5-gallon-tank-52003652/232057535509?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

I take it you just swap your existing pump over to this and voila.


Sent from my iPhone using Tapatalk

[Ωhm]

On 12/30/2019 at 8:59 PM, RestoringNV said:

Should I install a check valve, too!

I think so, traps prime (KEY ON) pressure, prevents fuel rail from draining back to the tank (long CRANK times).

[JustEmptyEveryPocket]

Couple of follow-ups from my original post:

 

21 hours ago, DirtyComanche said:

fuel from a sump

My truck's original gas tank rusted out. I bought the JP5A replacement spectra tank so that I could use a new cherokee style fuel level sensor. But I didn't like the idea of no baffle. So I cut out a ~12" square part of the fuel tank where the pickup tube sits and welded in a 5 sided cube. I placed it so that the vertical sides of the cube sat higher in the fuel tank, while the bottom of the cube sat below the original fuel tank bottom, to act as a sump/ baffle. There are also a few holes drilled to allow surrounding gas to flow into the sump, but not out of it easily. This has worked well for me. I can drive up (or down) steep slopes with my low gas light on and have yet to have an issue.

 

4 hours ago, Ωhm said:

I think so, traps prime (KEY ON) pressure, prevents fuel rail from draining back to the tank (long CRANK times).

I do not have a check valve and do not experience long crank times. But that is just one data point. YMMV.

 

For me the biggest plus is if my pump goes bad I coast to the side of the road and use common tools (in my Oh$#!& Bag) to remove the old one and install the new pump (which is also in my Oh$#!& Bag). I know other people claim to be able to replace the intank pump under the truck, but I just don't see how that is viable. For me, everything is right there, easy to get to and deal with.

[Minuit]

49 minutes ago, JustEmptyEveryPocket said:

For me the biggest plus is if my pump goes bad I coast to the side of the road and use common tools (in my Oh$#!& Bag) to remove the old one and install the new pump (which is also in my Oh$#!& Bag). I know other people claim to be able to replace the intank pump under the truck, but I just don't see how that is viable. For me, everything is right there, easy to get to and deal with.

The fuel sender can be removed with everything still in place. I think the service manual wants you to remove the driveshaft, but that's not necessary. If I had all the tools I needed (which amount to a chisel and hammer to drive the lockring off the sender, a screwdriver to undo a hose clamp, and whatever size the fastener is on the pump bracket) and a replacement pump, I think I could get the job done on the side of the road in an hour. When I did it originally, I dropped the tank, but that was before I knew you could do it without dropping the tank. Even still, the last time I dropped the tank on my 91, I timed myself - from starting to having the tank on the floor, it took me 23 minutes. I started with an empty tank and knew exactly what tools I'd need and in what order, but still.

 

The pump service on an MJ is really not that difficult. I do not see any normal use situation where the extra noise and re-engineering required for an external pump is worth it. How often is anyone really swapping a fuel pump out, anyway?

[JMO413]

I pulled my drive shaft the first time. That was when I replaced the sender. When I pulled it back out beacuse the hose popped off. I didn't remove the drive shaft. I think it total I spent more time looking for good fuel line hose clamps than I did removing and installing the sender.