3rd gen 4runner F-150 tank swap behind rear axle

[troyboy162]

just consolidating this now that i have real internet

the tank is a 1990-1997 ford F-150 rear gasoline tank. the diesel version is the same but its fuel pump will be different. the fuel pump that goes with the gas unit is close enough to the toy 3.4 unit (possibley others) that people have had this swap for years without issue. the tank sits in the stock spare tire location up and out of the way for the most part. so on with it...

the cost
I have about $350 into this mod. I had hoped to come in $100 less, but my tank source was pretty expensive at $225 for the tank/pump/sender and mount brackets. in the past people have gotten the tank/pump/sender for only $50

the tank
its 18 gallons (same as stock) and 34-3/4" x 27" x 7-7/8". you can safely pound that down to 25" by flattening the pinch weld on both ends(yup just like your wheel wells). the tank is also oddly deep in a small area at the rear. that can be pounded down as well without loosing more then a 1/4 gallon.

-they come in plastic too
-make your own air purge line so you can fill faster at the pump.
-evap (charcoal canister) line is 1/4" low preasure fuel line
http://i723.photobucket.com/albums/ww234/troyboy162/tank/13103599795883.jpghttp://i723.photobucket.com/albums/ww234/troyboy162/tank/13103599625612.jpg



the fuel pump
the ford pump ues nice quick release fittings. feel free to go through the trouble of adapting to them...or cut them off as most do lol. leave as much tube as possible to clamp to. I think it runs at roughly 35 psi and i worried hose clamps wouldnt hold, but they make special fuel hose clamps that do great at the job. The sending unit is said to have the wrong ohms for our system. feel free to put effort into making it work only as rough estimate...or dont even bother with it and use a ultraguage or scanguage.

-light motor oil on the pump seal 0-ring will aid in installation
-fuel return is 1/4" low pressure fuel line
-fuel feed is XX" high pressure fuel line
-fuel pump + is red, negitive is black
-toyota harness fuel pump + is blue/orange negitive is white/grey?
http://i723.photobucket.com/albums/ww234/troyboy162/tank/13103599368031.jpg

fuel filler hose
-45deg pre bent 2" exhaust piece
-2" fuel filler hose (expensive $19 per foot. measure three times lol)
-fits up high on the stock filler neck
-2" is not a tight fit for the tank or the neck but its close enough to hose clamp down
-air purge fitting is XX" on the stock filler neck
http://i723.photobucket.com/albums/ww234/troyboy162/tank/13105242470400.jpg

connecting to stock fuel lines
- 1/4 fuel return and evap fit perfectly
- fuel feed can clamp to the flange of the toy fuel feed line but this is ghetto. so far its working fine though.

http://i723.photobucket.com/albums/ww234/troyboy162/tank/13103598640080.jpg

2011-07-11_08-26-54_858 (http://www.youtube.com/watch?v=NPtQ8TCbJig#)










Tank mount
http://i11.photobucket.com/albums/a168/Sycosurfer150/Truck/Ford%20Tank%20Install/DSCN2300.jpg

Forward mounts



http://i11.photobucket.com/albums/a168/Sycosurfer150/Truck/Ford%20Tank%20Install/DSCN2312.jpg

You can see the forward mounts as well as the holes drilled through the bumper tube for the rearward mounts
http://i11.photobucket.com/albums/a168/Sycosurfer150/Truck/Ford%20Tank%20Install/DSCN2313.jpg

[Obi..]

:D Can I nominate this for a wiki? Seeing as it's basically usable for 2nd-Gen Runners also. :D

[DHC6twinotter]

I would love to do this swap for a 2nd fuel tank on my 3rd gen. Lots of other stuff that needs to happen first though.

Thanks for the write up Troy!

[troyboy162]

if it ports directly to the wiki that would be cool, but probably going to get more hits just being int he forum. I dont fully understand the motors the fuel pump will be ok on. id guess anything with lower/equal psi requirements and flow rate then the pump would work? ive only seen this on 3.4L

Dan it would be a sick second tank mod. bruceTS said they sell a 30+ gallon version if you wanted to horde gas lol.

[YotaFun]

The Bronco gas tank is 22 gallon just for reference but when I fit it into place, I would have just as much if not more hanging under the frame rail as the stock tank....

[NakSuKow]

The Bronco gas tank is 22 gallon just for reference but when I fit it into place, I would have just as much if not more hanging under the frame rail as the stock tank....


What year bronco? I would love a couple extra gallons.

[NakSuKow]

Troy, have you noticed any difference in the way the truck handles?

[troyboy162]

Troy, have you noticed any difference in the way the truck handles?


Yes it feels alot like the rear is loaded with camping gear. The back end is very dampened now, but is more prown to step out when playing on the dirt with throttle. Between the two changes i like it better so far. Hopefully the weight shift is good for wheeling

[4x4mike]

Interesting. I hadn't thought about the shift in location of weight. Might be a good excuse for the Icon adjustable shocks.

[YotaFun]

I think the bronco year I was looking at was 85 but they made the bronco till 96 so I am sure if you find one from a newer one it would work.

Probably a stiffer shock in the rear is in order now that the extra shifting weight is back there

[BruceTS]

I added airbags in the back to compensate, as for the weight shift, there really isn't much difference. The ford fuel pump has never given me a problem and once I drop the tank to adjust the fuel guage sending unit, I'll get pictures of the mods done to it. yea I need to add the fuel filler vent tube, sometimes it's a PITA to get a full tank.

[troyboy162]

just a update on this since its been a couple years. The quick ghetto cradle I went with and always had planed to upgrade, has been fine. I have dropped the tank a couple times and have duck taped cut up sections of the 2" filler hose to anything rubbing. The result is the tank ends up being pinched on the panhard cross member, the bottom of the truck body, and the rear bumper. Shockingly it is held tightly and somehow does not rub much. I expected the flexing of the frame and things to wear into the tank, but the set up is hardly wearing into the duct tape let alone the rubber hose below it. There are much better ways to hang the tank, but so far so good with the quick route.

The problems I have had are with fuel pumps. I have replaced two so far. The junk yard pump was horribly abused during my boil the fuel issues(dont point your exhaust at your tank!), but the other was a high quality OEM pump. The angle of the tank makes the evap vent on top submerged until the tank is 2/3rd empty. I believe the issues come from that since everything else is legit. I think either a vacuum or pressure is built in the tank and the pump can not over come it. I am trying a fancy 255 lph pump to hopefully allow it to work ok...so far so good. Fuel economy has not changed and the factory fuel pressure regulator appears to be fine with the higher volume.

[troyboy162]

updating again. The fuel issues continue. The higher volume pump has different symptoms since its more powerful but the results are the same where the truck needs to sit for a good 30-40 minutes. I have been researching the issue and believe its caused by either fuel starvation at the pick up or preasure issues due to the vent. I also think the new fancy pump has a failed fuel module since the truck can stall at stop signs with as much as 7 gallons in the tank. It just started doing that one day...maybe the extra power isnt a good idea?

nothing seems to be a good fix for the pick up other then maybe a clunk pick up or welding on a deep sump. The tank itself has no baffels internally. origanally I thought that was stupid and the root of issues. In the research I found that ford actually has a pretty high tech solution built into its fuel pumps. So much so that I think I will stick with the stock configuration for the most part. Possibly improving on it a bit for my own unique angled application.
looky here:
135

There is however the issue of the tank vent. I have not confirmed but I would imagine some damage has been done to the charcoal canister since filling my tank full or more dips the vent under gas for a considerable amount of time before enough is burned to uncover it. This guy fixed that issue in the hopes of filling his tank faster, but it should really solve my issues.
http://www.ford-trucks.com/forums/947654-did-a-fuel-tank-vent-mod-to-front-tank-mucho-better.html

I'm going to throw a new fuel cap at it too since a faulty fuel cap can create all the issues I've had and more.

[Seanz0rz]

That Ford fuel pump is awfully complicated!

Unlike the linked post, I would aim for rubber hose that is fuel certified. I've done some nasty stuff to hoses that were never meant to have fuel in them.

There is also flexible line from McMaster Carr that works well, I will have to track down the specific type though. It is what the VW guys use to replace the vent lines.

I'm not familiar with where it is on the tank, but for the evap vent line could you do a vent on the left rear and one on the right front, and tie them together? This way one is always exposed to fumes, no matter what the angle of the truck.

[troyboy162]

I'm not sure how it would work. I was going to try the rear seeing as thats the highest point on the tank, but then I saw where that guy mounted his at the same hight as the filler neck. No harm in putting it there (although I'll use better materials) and it keeps it so far up the charcoal canister will never risk gas pushed up into it again.

Also I found this if I want to try venting to the air in a troubleshooting effort. You can delet the charcoal canister. I'd rather leave it installed though since I believe it cuts down on your gas just evaporating off like it would.
136

[Seanz0rz]

Yeah, my 73 VW had a canister, earlier ones did not. The lines end up splitting and leaking. The solution is to move to the older style, where it just drips gas on the ground if you fill up in the cool morning and let it sit in the hot sun.

Also, think about how this will impact the smog check.

[YotaFun]

I don't know about the Cali stuff, but my buddy and I will be trying what I saw on Pirate4x4.
They cut out a square off where the pump and vent of the Toyota tank is and also too out the baffle and then cut a square where the ford pump goes and put the baffle in and welded the section from the Toyota tank to the ford tank, both utilizing stock wiring and venting.
They seem to have no issue, this will not be done till a couple of months but I will report once its done.

[troyboy162]

Thats not a bad idea but if I was to weld I'd just make a bad ass sump closest to the axle. You drill some holes in the bottom on the tank then weld on a square sump on the outside. that way the last of your sloshing fuel drops in and cant get out. I saw how the musle car guys do there tanks when they go to EFI motors with a old style cas tank.

[Kryptoroxx]

I don't know about the Cali stuff, but my buddy and I will be trying what I saw on Pirate4x4.
They cut out a square off where the pump and vent of the Toyota tank is and also too out the baffle and then cut a square where the ford pump goes and put the baffle in and welded the section from the Toyota tank to the ford tank, both utilizing stock wiring and venting.
They seem to have no issue, this will not be done till a couple of months but I will report once its done.

I was about to ask about the same thing. I am however no expert and would gladly pay for that small bit of work to be done right the first time.

Sent from my SAMSUNG-SGH-I727 using Tapatalk

[troyboy162]

Ive learned more....Something that should have come up much sooner lol, but clearly is part of my problem. Apparently the fuel tank preasure sensor is on the stock toyota tank and not on the charcoal canister. So... I havnt had that sensor after tank swap, and thats the part that allows the charcoal canister to actively vent to equalize pressure. Without it I have no idea how the venting would behave but I'm guessing not remotely close to right lol. When there is tank pressure its supposed to sense that and then vent it into your engine when running conditions allow it.

Its really a wonder how it worked at all over these last few years. Also a wonder how other people have been running without it. I would guess I have been floating between vacuum and positive pressure all these years and when I hit a extreme situation the truck gets vapor lock.

The canister is going to be deleted so that I'll be free venting through my remotly located roll over valve. I'll just run it that way in between smogs so long as it corrects my issues and dosnt let all my gas evaporate away in the summer.

Also I'm going to mod the fuel pump a bit to try and keep more fuel in the sudo sump. I'll try to take pictures of that.

[troyboy162]

heres a picture of the pump I took out. You can see the canister seperated where it snaps together. This should be what was making it stall at stop signs below 7 gallons. The angle of the pump would allow the fuel to pour right out and negate the "sump" effect it gives to the tank. This leads right into the mod I tried
http://i723.photobucket.com/albums/ww234/troyboy162/IMG_20140213_183543934_zpsee1lqpc1.jpg

heres a pic of my ghetto mod. All I did was seal the pump up with JB water weld all the way up to the top corner( the hole for the stabilization tube is sealed inside too). I left a few holes unsealed in the top corner in case its designed to vent through that seam. This should hold the fuel level much higher in the sudo sump and lead to all things desirable while I starve the fuel pick up in the un-baffled tank. Something came up late in research though lol. Turns out traditional JB weld that people have sworn by for years now dissolves with today's fuel additives particularly in California. Its most likley not the ethanol said one chemist, but one of the additive package items added to pump gas. I have another epoxy holding my purge fitting on the tank that has been fine for years but this use is alot more exposes no to mention sloshing fuel will contact it. I'm adding a jb water weld chunk to a jar of gas to watch for break down.
http://i723.photobucket.com/albums/ww234/troyboy162/IMG_20140214_092652061_zpsnctyi7da.jpg

[troyboy162]

Tank vent solved with expensive fittings... But there is no possible way to put the vent under water now. I also deleted the charcoal canister and will try free venting for awhile. The change back to a smog legal system takes 5 minutes.

http://i723.photobucket.com/albums/ww234/troyboy162/long%20travel/IMG_20140219_222704501_zpst4w5evyb.jpg (http://s723.photobucket.com/user/troyboy162/media/long%20travel/IMG_20140219_222704501_zpst4w5evyb.jpg.html)

[troyboy162]

hmmm today I burned 19.6 gallons out of my 18 gallon tank and I didnt even run out of gas. Ive read some people call it a 22 gallon tank and that may be more correct seeing as I took way more then 18 out when I drained it as well.
The fuel pump mod is working i'd say!

[Seanz0rz]

Good news!

Just curious, and don't want to surf through the thread, did you remove the rear cross member? And if so, what did you replace it with? I'm thinking about cutting mine out and replacing it with something higher up.

[troyboy162]

I have the spare tire cross member removed and the front stock gas tank cross member cut out. But I have a sorta cross member in my transfer skid and two extra ones in my rear bumper.

[troyboy162]

update on the water weld:
zero deterioration after two months in a jar on my kitchen counter. Thats with 87 octane cali gas. The small details such as my fingerprints are as sharp as the day I made them. The test is over since I'm tired of a having a jar of gas in my kitchen lol.

[Seanz0rz]

HAHA!

I used some of the quik steel or whatever stuff to fix a hole in an evaporative cooler, hopefully we will get one more year out of it. It is holding so far.

[4x4mike]

update on the water weld:
zero deterioration after two months in a jar on my kitchen counter. Thats with 87 octane cali gas. The small details such as my fingerprints are as sharp as the day I made them. The test is over since I'm tired of a having a jar of gas in my kitchen lol.

:Like:

[troyboy162]

my thoughts when I first made this were that the truck would not be A) driven fast or B) jumped. Well those two things are not true anymore so I needed to contain the fuel tank from the top as well. I found a really easy solution that looks like it will work great.

This is nothing more then metal strap over top of the cradle I made. The strap is thin enough to conform to the tank when cranked down and mates it solidly to the cradle. There no more possibility of the tank moving. While making this upgrade I saw the tank had already slightly moved from the spot where it had been for years.

and the picturres are a little poor but I think it shows how it all works.

This is where the strap is tightened. That is either a grade 5 or 3 long bolt. I had forgotten how soft they are, but it works for this. The picture dosnt show it very well but the strap is running along the bottom support. The bottom support curls upward over the edge of the tank so that the strap only pulls down and not rearward on the tank
http://i723.photobucket.com/albums/ww234/troyboy162/long%20travel/IMG_20150102_161650310_zps8cgc5wcm.jpg

heres the strap coming down to the rear of the truck. Its just tied in at the rear mount bolts.
http://i723.photobucket.com/albums/ww234/troyboy162/long%20travel/IMG_20150102_162132854_zpshbk5oisp.jpg

[troyboy162]

Alright...I just had two more fuel pumps die. One that lasted a year and the replacement that lasted three weeks. That means the fancy venting modifications I did were not helpful and the possibility of faulty pumps is now near zero. Its probably something dumb like low voltage to the pump causing overheating...Fun times. This last pump did not get weak slowly. It went from fine to maxed short term fuel trims instantly.

I have researched like crazy on the subject trying to find some smoking gun to why these ford pumps will not work for me. There is no reason it shouldn't. Ive even learned that the toyota tank does not have a pressure sensor in it as I once though. That means the evap system can even work properly and, when hooked back up, did so that I could pass smog. Differences in PSI and flow are handled by the fuel pressure regulator. You can mount a slew of pumps behind that regulator without issue The FPR and ECU would make sure everything is fine. The only differences in this system are the sumps. Ford has a module and Toyota has baffling built into the tank.

Part of me wants to move to external fuel pumps, but they are known to fail more often do to the elements and increased heat without a bath of fuel to cool it. External pumps really only offer ease of replacement/install while suffering in every other category.

More fun to come soon haha.

[YotaFun]

Interesting info.

I am curious as well how the one pump lasted so long but the other only a few weeks if that.
You said that you hook the evap system back up to pass smog, was that around the same time frame you installed the new pump?

I remember reading a thread sometime last year where some one had actually cut a square section of Toyota tank, pulled out the baffle, cut a match hole in a new tank, put the baffle in, and then welded in the Toyota tank section so that everything essentially stayed stock.

I will try to search around to see if they have had any issues with the set up, this may be an option?

I am unsure how the module in the ford works vs. the for baffle, maybe if the module detects the fuel flowing about in the tank and slows down the pump when it gets air over fuel into it?

[YotaFun]

After reading it all, getting a huge headache trying to not get dizzy from all numbers and how the pictures are taken, it makes sense and is a very clean install... http://www.toyota-4runner.org/3rd-gen-t4rs/194378-ford-f150-gas-tank-swap-into-2000-4runner.html

[troyboy162]

that swap of the toyota stuff looks great but that is a ton of work. I dont have my toyota fuel tank anymore so that route is out of the question anyhow due to cost. The ford unit should be fine so I lean toward finding some install issue like there is low voltage at the pump or something equally invisible, but important. Maybe particles from my water weld make there way in and ruin the pump. Maybe the smaller effective baffle of the ford module allows recirculated fuel to trap too much heat. Maybe these are really junky pumps and my abusive driving and frequent low fuel levels just eat them alive. Tare down and autopsy will be this weekend.

Today I'm back to looking at external pumps, not because they are a good option, but because I can change one on the side of the road in 5 minutes and that's where I am scared to be stuck again. Even if I find a resolvable install issue; I've got the fear in me now lol.

Also the ford module is just a pump with a housing that acts as a baffle/sump for a tank that does not have one. I've read now that its a common approach used by lots of manufactures these days since its very effective at keeping the pump pickup in fuel. The return line dumps into the bowl so it continually recirculates the fuel up to the regulator and then sips more fuel as needed from the sock filter on the bottom of the module. That way the sock filter on the bottom can be out of the fuel for extended periods as the pump lives off whats in the module reservoir.

[troyboy162]

testing completed and the results are bad lol. The fuel pump is getting proper voltage and the voltage drop between the pump and battery is only .7 volts. That could be a bit better, but its not cause for alarm.

What is a cause for alarm is this fuel pump did not die. The valves in the pump module are malfunctioning. When you fire it up it just spews out fuel from the seams on the module. that means the check valve is stuck closed or the shuttle valve is messed up. When the pump is divorced from the module it works just fine. The bad valves may be a result of the water weld cracking off contaminate into the module, but it would have to pass through the pump to enter those valves and the screen filter on the pump itself is fairly fine.

In other news there is no way to use the module with a external pump. The internal check valve on the module means you could never vacuum fuel up and out.

Probably not a good idea to keep messing with these ford pumps. Sure I probably caused some of those pump deaths, some were probably defective, but its not working out for me.

I'm staring down these two options:

1. make a access door in the rear so I can keep changing out ford fuel pumps easily.

2. put baffles in the tank. Modify the pick up, and proceed with a external or internal pump.


Truck is gonna be down for awhile lol

[troyboy162]

Game over... my buddy had a tank he didn't need from a 98 4runner. Toyota baffles and pickup grafted in. I'm paying him to weld it up since hes good at that. Best investment I've made in the truck in a long time.
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160712_214947_01_zps3sd2e0vh.jpg

[Kryptoroxx]

How does everything work now?

Sent from my SAMSUNG-SM-G870A using Tapatalk

[troyboy162]

How does everything work now?

Sent from my SAMSUNG-SM-G870A using Tapatalk

Not yet installed but I don't expect any surprises. The Toyota system is a classic bucket and pick up. Not much to go wrong and with a Denso pump it should be a 200k mile solution like we have all seen on these trucks. Knock on wood of course lol, I'm nervous about fuel pumps these days

The baffle is not in the center of the tank like it should be, but my tank is at a tilt anyhow and there is a cross member in the way of mounting anything on the outside of the middle of the tank. The baffle is slightly forward and that may be the ideal spot anyway given the tilt.
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160713_092827_01_zpswhh5rim7.jpg

The pick up has been modified to reach back into the tank further to meet up with the better baffle location
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160713_092833_01_zpsolurcphe.jpg

Patchwork quilt style so that the pick up could be seen while it was modified.
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160713_092850_01_zpsl0yjblux.jpg

[Kryptoroxx]

Not yet installed but I don't expect any surprises. The Toyota system is a classic bucket and pick up. Not much to go wrong and with a Denso pump it should be a 200k mile solution like we have all seen on these trucks. Knock on wood of course lol, I'm nervous about fuel pumps these days

The baffle is not in the center of the tank like it should be, but my tank is at a tilt anyhow and there is a cross member in the way of mounting anything on the outside of the middle of the tank. The baffle is slightly forward and that may be the ideal spot anyway given the tilt.
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160713_092827_01_zpswhh5rim7.jpg

The pick up has been modified to reach back into the tank further to meet up with the better baffle location
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160713_092833_01_zpsolurcphe.jpg

Patchwork quilt style so that the pick up could be seen while it was modified.
http://i723.photobucket.com/albums/ww234/troyboy162/Mobile%20Uploads/IMG_20160713_092850_01_zpsl0yjblux.jpg
I understand your nervousness lol! You've had quite a time with this mod. I definitely have my fingers crossed for ya.

It certainly looks solid though. I have high hopes for success.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[YotaFun]

This is probably the best solution to doing the ford tank.
I have a spare tank at my parents I think, so once we are settled into the new house and pickup a welder, its on! lol

How much is a new pump? just peace of mind, throw a new one in?

[troyboy162]

The new pump from denso was only $80. It didn't come with the bottom rubber piece so that was reused. No worries with that since it's just a spacer.

Also don't cut the sealing surface off like my buddy did lol. It leaks bad and I'm going to have to use sealer.