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Where to mount electric fuel pump

5K views 38 replies 10 participants last post by  cerial 
#1 ·
In response to my possible vapor lock issue on my 68 Ford Fairlane, I'm thinking about going with an electric fuel pump.

I've mounted these on other cars but my Fairlane seems to prevent a problem. Your supposed to mount an electric pump below the tank since they push fuel.

The bottom of the tank seems to be the lowest thing on the car other than the spring shackles. I thought about mounting it on the frame rail but the tank is still lower.

This photo is horrible since the car was never undercoated but you might see the fuel tubing. This is about halfway between the tank and engine.

Could I just cut the tubing here, remove a section and mount the pump here? As long as I have flow going to the pump does the location really matter?

Or does the pump really need to be near the tank?

I realize the pump needs head pressure to work. I work at a chemical plant.
 

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#2 · (Edited)
In response to my possible vapor lock issue on my 68 Ford Fairlane, I'm thinking about going with an electric fuel pump.

I've mounted these on other cars but my Fairlane seems to prevent a problem. Your supposed to mount an electric pump below the tank since they push fuel.

The bottom of the tank seems to be the lowest thing on the car other than the spring shackles. I thought about mounting it on the frame rail but the tank is still lower.

This photo is horrible since the car was never undercoated but you might see the fuel tubing. This is about halfway between the tank and engine.

Could I just cut the tubing here, remove a section and mount the pump here? As long as I have flow going to the pump does the location really matter?

Or does the pump really need to be near the tank?

I realize the pump needs head pressure to work. I work at a chemical plant.
Wherever you put it, it will probably work fine as it has to draw some vacuum. Just make sure you don't mount it where the hoses can get easily snagged if you accidentally run over stuff and keep away from exhaust. In a street car I would mount it where it fits the best, and this is where you are describing. Mount the pump on rubber on something solid or it will be noisy. Don't forget to use a fuel pump relay, proper gauge wire, and to bypass the mechanical fuel pump.

p.s. I like old Fairlanes - in the past I had a 67 390 GT and a 69 Fairlane 500 2Dr HT pretty much just like yours.
 
#3 · (Edited)
If the tank sits lower then the frame your only choice is an in tank pump.

Electric fuel pumps can not "suck" fuel they must be submerged at all times to work properly.
I have had them pull fuel up to the top of a tank before, then had the line drop down. But this severely reduces the pumps life. Your better off with a in tank pump that minimizes the lifting.

If your tank is low one other option is a sump between the tank and diff. Your using the diff as protection. Then you can mount the inline pump next to the sump.

This requires dropping, drying, cutting, and welding, your tank. But the final result is something that will keep that pump fed.
A small v shaped baffle on the sump itself installed before welding will help to keep fuel in the outlet and inlet port area so during hard acceleration you do not have starvation. Ideally the sump would be mounted in the back of the tank to prevent this. But I assume it would be highly exposed there.

I have simply emptied a tank in the past, dropped it, dried it, found a double wall corner on the side without exhaust, drilled that corner as low as possible, tapped that corner, installed a male to tap/male to compression fitting to female compression fitting. Which let me snake a line against the bottom of the tank. I then ran the line to the to the pump which was located in the corner by the axle.
I tig welded around the tapped area sealing in the threaded male fitting in there. It worked.
I fed the return line to a T in the neck using that vent line(there were additional
vents) as a return line to prevent needing to tap the tank again.
I would have been better off using an in tank pump.



Your best bet here is to drop the tank and install an intank electric pump, new sending unit, and new straps. Run flexible lines off the top of the pump to the side of the frame. This allows for easier tank installation/removal as well as allows you to keep your hard lines mostly straight.

Install a regulator with return. The regulatior will maintain a set psi of fuel which depending on the size of your rail/floats should be enough to prevent starvation even when the front wheels lift. The return will circulate the fuel keeping it cool while filtering it more.
 
#4 ·
Low and close. Some pumps don't self prime well, others do. For those that have priming problems you just prime them the first time and they are good to go as long as you don't run the tank dry.


Modern fuel is designed for fuel injection so it from the electric pump, which is in the tank, to the injector is under pressure. Since injection has all been sequential, port injection since 1996 and some back as far as 1986 or 87, there is scant time for vaporization which must take place in the cylinder. So modern fuel has a lower vapor point than old fashion carburetor fuels to facilitate quick vaporization. For a carb'ed engine with a mechanical pump on the engine pulling fuel the length of the vehicle this has led to significant vapor lock issues.


My preferred method on the street is to use an inline pump intended for older low pressure TBI systems choosing a version that develops 20 psi max. Then plumb this to a bypass regulator under the hood such that you furnish the carb with 5 to 6 psi while the remainder returns to the tank. A bypass prevents forcing the pump to work against a near dead head when the engine is idling which keeps pump and fuel cooler. The bypass can return to the tank by purchasing a flex length of filler pipe hose with a vent tee in it. Or tee into the feed line ahead of the pump, this gives the looped fuel a little time to cool before going back through the pump. Self bypassing pumps tend to overheat the fuel and you end up back at vapor lock. So even on a self regulating pump set it higher than the carb needs, use a bypass regulator at the proper pressure under the hood then send the difference back to the pump intake side. Arrange the regulator so the feed line to the carb is as short as reasonable. Use fuel injection hose where hose is used as it is designed for higher pressures should regulation go wrong to the high side.


Electric fuel pumps should get their power from a 3 way oil pressure switch. This switch turns on the pump when cranking then switches over to controlling the pump in the run position of the key switch as it sees oil pressure. In an accident, if oil pressure is lost because the engine stalls or is shut off for other conditions beside the turned off with the key switch, the loss of oil pressure shuts off the pump preventing fuel spillage at the carburetor.


Bogie
 
#5 ·
I had horrible luck with a Barry Grant pump mounted about even with the center of the tank, it would suck air and never recover unless the tank level was above the pump. No other changes than replacing it with a Holley "black" in the same mount and it would run (way below 1/8 on the gauge) until I'd get nervous enough to fuel up.

Russ
 
#6 ·
Until I can get on my computer, so I can elaborate more, I came up with an idea. Why not "glue" a bracket to the bottom of the tank so the pump will sit below the tank and use the drain port to feed the pump?

The drain port is a 1/8" NPT pipe plug so I'll have to feed the pump using a 5/16" fuel nipple then use a 3/8" outlet coming off the pump to feed the fuel line above the sending unit. Then just cap off the port on the sending unit.

The line coming off the mechanical pump is 5/16" anyway.

My theory is since an electric fuel pump will flow more, eventually the line will fill up with gas when the float valve is closed.

Since this is not a high performance 302 engine (2 barrel Autolite at that) I doubt fuel starvation would be an issue.

So what about this glue? I have used 3M structural adhesive, RTV and if it has not dried up I've got a tube of some 3M urethane leftover when I glued the windows into their tracks.

Just get the surfaces down to bare metal, apply it and use a sissor Jack to hold it in place until it cures . I've actually done this before.

See where my finger is pointing. This is where I want to mount the pump. Only issue is I need to be careful and not hit something and rip it off since the car is lowered.

I pulled the plug out and gas shot out like gangbusters.

Only a bit of crud came out. Not bad for a 51 year old car.

Also I took a photo of a fuel pump I mounted on my turbo Yugo if you can see around the cob webs. This car has been off the road for sometime.

Its a GM throttle body pump. More on that later. That was mentioned as a suggestion. That is a story in itself. I'll comment on that later.
 

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#8 ·
If I am looking at that correctly using that plug then dropping down an inch to a 2" diamiter pump is going to put that pump below the diff.

That is a no on safety in my book. Thats actually saying something. I would drive something with only one wheel to stop before running a lowered car where the fuel line could be ripped free. I have scraped tanks over speed bumps before in lowered rides. It is not something that you do twice before fixing the issue or installing protection.



Your left with raising the tank, installing a smaller tank, or installing an in tank pump.

I would go with an in tank pump here.



Panel bond is amazing stuff. My money is on the gasoline breaking it down over time though. You may get several months out of it sealing. But eventually I feel it would fail leaving you with a slow leak that would quickly turn into a larger one.


Get an in tank pump.
 
#9 ·
I was talking about just using the urethane or panel bonding epoxy to secure a mount to the bottom of the tank then bolt the pump to that. Since I don't want (or can't) drill holes in the bottom of the tank to mount the pump directly to the tank. Be yeah, your right, I really don't want the pump vulnerable. Just trying to come up with ideas.

While re-thinking about it, I have another idea. The original tubing points upward runs, makes a bend, runs along the body, then down again. In other words the way the original tubing is routed that would not provide any head pressure to the pump. Since I guess the original mechanical pump "sucks".

My current idea is to still use the drain port and run a new metal line along the bottom of the tank and downwards to the frame.

Then mount the pump to the side of the frame there like most people do and connect the original tubing going to the engine to the outlet of the pump. Well this is a uni-body car but you get the idea.

As long as I have good flow to the pump, is that all that matters?

As far as using an in-take pump goes. I looked into this but so far have not found anything that doesn't cost a couple hundred dollars. Also I've been struggling to get the original sending unit out. It's rusted pretty bad. It's just like the one on my MGB using the collar.

I was going to replace it while I had the tank drained. For some reason the guage only goes to 3/4 tank but is accurate once it get's below 3/4 tank. I also thought that there was a bronze sock on the pickup that might be getting plugged but someone told me they didn't start installing these until the early 70s. Since I drained the tank and nothing came out, I don't think having a plugged pickup is the problem anyway.

My 77 MGB uses an electric fuel pump mounted below the trunk and just a supply line going to the carburetor. No return line or regulator. I have never experienced any vapor locking with that car. In fact it's one of my easier cars to start in hot weather. That's why I'm wondering if it's really necessary to run a return line back to the tank.

I hear what your saying and all. I turbocharged my Yugo and had to drop the tank about three times before getting it right. I ended up having to use the 5/16" vapor line as the new return line. I drilled a hole in the bottom of the tank and soldered a fitting for a 3/8" fuel fitting. This is what supplies the GM throttle body fuel pump. I had to use a larger return line because my regulator couldn't dump enough fuel back so I flooded the carburetor at times. The pump I used was for a GM throttle body and deadheaded at 20 PSI. There are currently no hoses connected to the sending unit.
 
#10 ·
I can't say I'm crazy about the exposed position nor the attachment method. The OEM's go to great lengths to use structure to protect the fuel lines with good reason. Especially with an electric pump that will keep on pumping till the electricity is shut off this is a big concern. Having seen a few fuel fires in my life it's not something I want to participate in, thank you very much.


Bogie
 
#13 ·
I know they make fuel pump mounts. They look like miniature motor mounts.

But I've got some black rubber material about 1/4" thick I found somewhere. I was planning on cutting out of piece the size as the base and placing it between the frame rail and pump.

I did the same thing when I mounted that GM throttle body pump to the body on my Yugo. I can't tell that there is much vibration.
 
#14 ·
Some thick rubber won't do much if the bolts will transfer the vibration. The little motor mounts are the way to go. Although if you use what you have, you can help it further by making rubber washers from the material to help isolate the vibration through the bolts.

As far as the location, I'd go with your original location and a Carter pump will self prime no problem. Once the lines are full of fuel the pulling effect is sort of minimized. A Carter will do the job just fine. With the Carter the mounting is improved also, as it hangs from 3 rubber bushings and they sell an additional frame mount kit. I didn't even use the motor mount kit, but my car is a little loud.
 
#15 ·
Getting back to your original problem. I don't think a electric FP is the answer. I would look at the float and needle in the carb. Clean it up. Crank the engine with the line to the carb disconnected to see what kind of flow you are getting. Clean out the fuel lines and tank . This car ran good for years for you. Just needs attention. You won't like the E FP.
 
#17 ·
Well it ran good for years until it get's into the 90s and is idling in drive throughs. If it was a fuel starvation issue with the float valve, looks like the car would start starving for fuel on the highway.

Before this happened, I drove over 5 miles at 60 mph. I stopped a PetSmart to pick up some cat food, then drove to a Popeye's less than 1 mile and that is when the car started idling rough in the drive through.

The car seems to require to idling for about 10 minutes before this happens.

I believe this is why it has never done this at a red light since red lights usually change before 10 minutes.

First time this happened was at an ATM at my bank. There is always some goober in front of you taking their sweet ***** time.

I'm going to rig up a piece of clear poly tubing between the mechanical pump and carb and see what happens. And see if I can actually induce a vapor lock condition on my property. Maybe use a hair dryer to aggravate the problem.
 
#19 · (Edited)
What I have not seen mention is if this were to happen again, what can I do about it so I can be on my merry way and not have to wait hours for the car to cool down before it will start?

I heard of dousing the fuel pump, fuel lines and carburetor with water. I don't know if I would want to risk thermal shock on my engine by pouring water onto it.

Could you just disconnect the discharge line off the fuel pump to relieve any pressure built up in the line?

I thought I might try insulating the fuel line coming off the pump to see what effect this has before retrofitting an electric pump. Dumb question but I found a better place for this pump. It's closer to the tank but I'd have to mount it at 45 degree angle, sort of on the inside panel opposite of the rocker panel, right at the wheel well. I don't mean inside the wheel well or where it's vulnerable to road debris.

The tubing points downward at a 45 degree angle so could I mount the inlet of the pump in this direction?

As far as a return line. Running one is not out of the question. I could always run it along the supply line, drill a hole in the trunk and connect it to the vent line coming off the filler neck instead of dropping and modifying the tank.

I just need about 10 to 15 feet of tubing...
 
#20 ·
Back in the "Good Ole" days it was found that attaching spring loaded clothes line clips to the fuel line helped. I can't really see why given that wood isn't a good heat conductor but does provide some insulation.


I've never been too keen on insulating fuel lines as this is as good at keeping heat in as keeping it out, so you need to be selective about where you do this.


Given that it's unknown if the problem is before or after the pump watering the fuel line where you can get at it is an experiment. A heat shield between the line and the engine might help both be reflecting engine heat away and if against the line, providing some fin effect surface cooling which of course can work in reverse and add heating surface, another experiment.


I have wondered but never done a variation on the clothes line clip thing be using spring steel paper binder clips to add "fin" area to the hard lines. One more experiment.


I live on the wet, cool side of the mountains, summer isn't over but we already moved into fall so cooking fuel systems isn't a problem here. Beside for my own rides I use fuel delivery systems exactly as I describe. For my adventures to the desert side of the mountains I've not had any issues with this set up.



Bogie
 
#22 ·
Before I install this electric fuel pump, I was going to try this "special" fuel filter first. This filter has some sort of liquid/vapor separator inside it that purges vapors out a 1/4" line.



https://www.oreillyauto.com/detail/...05/6bf814fc80d2/wix-fuel-filter/33040/4832394

I had him order the store brand for $5.99 and will pick it up today after work.

There is also a filter with a 3/8" inlet/outlet, WIX part# 33041. BTW.

It's for a Jeep/AMC application. Not sure what the 3/8" version fits. Apparently it was to address vapor locking issues when unleaded gas was introduced. The 1/4" line is supposed to be routed back to the vent line coming off the fuel tank. The guy at O'reilys said it could also have been routed to the charcoal canister (some models).

I don't know what's inside it. Whether there is some sort of pressure relief valve under the 1/4" nipple or it actually separates the fuel from the vapors. Either way it's supposed to relieve pressure.

I was going to remove the fuel filter that screws into the carburetor, install a fuel fitting in it's place, replace the metal line with a piece of hose, insulate it and install this filter near the carburetor. That metal line comes very close to the timing chain cover and think it could be acting as a heat sink.

As far as this 1/4" mipple goes, if all it does it vent vapor, I was just going to run it straight to the ground. I could possibly vent it back into the air cleaner. That might cause the engine to idle a bit rich while idling in drive throughs for more than 5 minutes. I don't know what the outcome of that would be. I guess it's better than idling too lean from running out of fuel.

My only concern is the hose may puke gasoline at idle. However it can't be any worse than fuel boiling in the fuel bowel and running all over the place. All the intake manifolds and carburetor bases on my carbureted cars are stained yellow.
 
#23 ·
Before I install this electric fuel pump, I was going to try this "special" fuel filter first. This filter has some sort of liquid/vapor separator inside it that purges vapors out a 1/4" line.



https://www.oreillyauto.com/detail/...05/6bf814fc80d2/wix-fuel-filter/33040/4832394

I had him order the store brand for $5.99 and will pick it up today after work.

There is also a filter with a 3/8" inlet/outlet, WIX part# 33041. BTW.

It's for a Jeep/AMC application. Not sure what the 3/8" version fits. Apparently it was to address vapor locking issues when unleaded gas was introduced. The 1/4" line is supposed to be routed back to the vent line coming off the fuel tank. The guy at O'reilys said it could also have been routed to the charcoal canister (some models).

I don't know what's inside it. Whether there is some sort of pressure relief valve under the 1/4" nipple or it actually separates the fuel from the vapors. Either way it's supposed to relieve pressure.

I was going to remove the fuel filter that screws into the carburetor, install a fuel fitting in it's place, replace the metal line with a piece of hose, insulate it and install this filter near the carburetor. That metal line comes very close to the timing chain cover and think it could be acting as a heat sink.

As far as this 1/4" mipple goes, if all it does it vent vapor, I was just going to run it straight to the ground. I could possibly vent it back into the air cleaner. That might cause the engine to idle a bit rich while idling in drive throughs for more than 5 minutes. I don't know what the outcome of that would be. I guess it's better than idling too lean from running out of fuel.

My only concern is the hose may puke gasoline at idle. However it can't be any worse than fuel boiling in the fuel bowel and running all over the place. All the intake manifolds and carburetor bases on my carbureted cars are stained yellow.

You WILL need a return line to the tank with that filter! When not purging vapor it will be bypassing fuel. I tried the same filter and return line and it fixed my problems by about 95%. Still at WOT for a stretch it would "run out of gas" when real hot.
 
#29 ·
I am using copper for my vent lines mainly because they are highly visable. Worst case it cracks and vents to the atmosphere till i notice it.

But I would never use it for a direct fuel line.

Use rubber line. In most cases fuel injection line is only 1 to 2 dollars more a foot and better built.

Brake line will work well for straight stretches using rubber for bends. Double flare the ends and double clamp for years of trouble free issues.
 
#30 ·
I'd order some Ni Copp line, 25' rolls are pretty cheap now on Amazon. Also go as large as your fuel line coming in.


Oh, and no guarantee's. Like I think I mentioned on mine it fixed the problem 95%. Only when going WOT with a 454 from nearly a stop, at about 70mph it would still sometimes "run out of gas". The electric fuel pump fixed that. I even had a 1/8" insulating spacer on my mechanical fuel pump.
 
#31 ·
Good point on the copper tubing. Years ago when I built my first turbo system I had used copper tubing for the oil supply line and it cracked at the fitting going into the turbo. I forgot about that.

I picked up that "special" AMC/JEEP fuel filter with the 5/16" ports and the 1/4" "vapor" port with the small orifice yesterday from O'Relieys. It's the store brand version so I got it for $5.99. The WIX filter was $20.

I capped off the outlet port with my finger and blew through the inlet and heard air coming out the 1/4" port so doesn't look like I could just run a line coming off of it to the ground. So as Tony says, It would most likely puke gasoline as the engine is running.

Since everybody (on Youtube anyway) seems to have their own version of how to cure this vapor locking issue on their old cars, I've been thinking of ideas since I can't be working on my car.

If running an electric pump and a return line is the only option, I'll do it but I thought of another idea requiring less plumbing that might allow me to keep my mechanical pump.

First I'd install a 3/8" check valve in the hose between the pickup tube on the sending unit and tubing going to the pump. I've got one coming. That way no fuel get's pushed backwards into the tank.

Place a TEE (or this three port filter) before the carburetor and run the smaller line into another TEE before the mechanical fuel pump. This would create a closed loop fuel system. I might have to plumb in a regulator before the carburetor just in case (couldn't hurt anyway). I don't know if feeding pressurized fuel before the pump would multiply the fuel pressure. The reason I wonder is I've heard of people running fuel pumps in series on turbocharged engines to boost fuel pressure.

I've also heard of people tapping into the weep hole on mechanical pumps to increase fuel pressure under boost applications. I believe Paxton used this method back in the early 70s on their centrifugal blower systems.

Getting rid of the heat: Running a closed loop system wouldn't do anything as far as reducing the heat from the fuel. Since heat is the main cause of this. It may make it worse, so that is a concern. But would help equalize the pressure and reduce any voids in the fuel lines.

From what I've read, the mechanical fuel pump is a heat source itself since it's mounted to the engine block. But if this is where vapor locking is starting at then an electric pump upstream maybe the only way around it.

Before sending the fuel coming off the tee back to the pump, I've got this small transmission fluid cooler I could mount in front of the radiator so the fuel could be cooled before returning it before the pump. That maybe required after all. I'm trying to visualize what's going to happen. I was going to use clear poly tubing as fuel line while testing so I can see what's going inside the fuel lines.

I realize this sounds like a Rube Goldberg contraption and all.

One sure way to test this is to zip tie the fuel line going to the carburetor to the upper radiator hose and let the engine idle. That would maximize heat transfer. If it passes that test, then it should work.

I've actually got all of this stuff already so it's not like I'm going to have to spend allot of money on brass fittings and parts.

Something else that comes to mind. When the fuel in the line starts to boil and expand after I shut the engine off, I'm wondering if fuel is being pushed past the float valve. And that's what causes fuel to leak all over the carburetor during a heat soak. That's why I wonder if installing a regulator might be of some benefit in that regards.

I'm still convinced this issue has more to do with the 10% butane content in gasoline than the ethanol!

Adding the check valve at the tank might be of some benefit anyway. Because on both incidents when the car stalled on me, I pulled the 3/8" hose off going to the fuel pump, there was no fuel in this hose. Just a few dribbles. I would have expected some fuel to pour out. I kind of wondered if there was some void in the line going to the pump. Maybe the exhaust or hot asphalt was actually heating the fuel in the line before it even got to the fuel pump. On some of my other cars, the fuel line runs inside the cabin to protect it from the elements. Ford chose to mount the tubing on the frame rail and inside the front wheel well on this car!

My boss told me his parent's were driving through the Arizona desert in their 2005 Toyota Previa minivan and the engine just quit. They had it towed to the dealership. The dealership said that the asphalt on the interstate that day was so hot, it actually caused the fuel in the lines to get hot and boil. This is on a modern fuel injected vehicle!

Apparently they have seen this before. They just let the car cool down for about 12 hours, the van started up and they said, "you are good to go!". That was their fix.

So apparently this problem doesn't happen to old carbureted cars but modern fuel injected cars as well.
 
#32 ·
I hate to beat this subject like a dead horse and all....

After thinking this thing through, looks like I'm going to just mount this electric fuel pump I got on my 68 Fairlane, insulate the supply line in the engine compartment and see what happens. If I still have issues, I will tee off at the carburetor run a fuel return line back to the tank.

Once last question. Any chance this vapor locking issue is happening in the line before it even get's to the mechanical fuel pump and not after it as I visualized?

The fuel line runs on the bottom of the car instead of inside the cabin (like some other of my cars) protected from the elements. My car is also lowered about 4". So I got this 10 to 15 foot exposed fuel line sitting 6" off the hot asphalt which is probably well over 130 degrees on a 90 degree day. So if the fuel is vaporizing in the line before it even get's to the mechanical pump, could that be what's happening? Also considering the length of the line. That's allot more fuel to get hot while idling and allot more work the mechanical pump has to do.

From what I've read a mechanical fuel pump basically just creates a negative pressure on the fuel line. They don't actually "pump". This acts like a straw to draw the fuel out of the tank. So if fuel is boiling or turning to vapor in this section of line, it could be even pushing fuel backwards into the tank causing an even bigger void in the system. Kind of like trying to suck the last bit of soda out of the bottom of a drink cup filled with ice. Is that a good analogy?

So by pushing "cooler" fuel from the tank using an electric pump, should force or compress any vapor that may build up. That's the theory. Unless of course the pressure in the line exceeds the pump pressure.

I'm starting to wonder if the fuel line almost touching the timing chain cover was what was causing my problems all along but I like the idea of being able to pump fuel after the car sits for awhile without having to crank and crank. So I'll see what happens.

So after racking my brain on where to mount this electric fuel pump, I watched this video and BINGO!

Skip to 1:58 on this Youtube video. He's installing EFI on a Chevelle but the under the rear end of the car looks just like my Fairlane. He makes a bracket, bolts it to the underside of the trunk and mounts it parallel with the bottom of the tank. Sweet!



The pump I bought is made by Carboyle. But they don't even have a corporate website! It looks like a rebranded version of the Mr. Gasket 12S that sells for twice as much and other pumps on Ebay. It has the same specs as the Mr. Gasket 12S pump. Just another example of rebranding. It's probably made by a company in China and 10 different companies just put their name on it.

I downloaded the instructions from Mr. Gasket's website because this pump came with no instructions. I know how to wire up a fuel pump, I just wanted to know if it said anything about where and how to mount it.

It's not very forgiving! The pump has to be mounted 12" from the fuel tank supply and it has to be clocked at a 45 degree angle with the outlet pointed upwards. It doesn't say anything about mounting it vertically. Any idea why mounting it at a 45 degrees angle is required?

I hear complaints about electric fuel pumps failing. I wonder if it's because people ignore where to mount them. You can pick an ideal place to mount a fuel pump on any car but that doesn't mean it's going to work.

A friend once mounted one of those Facet cube pumps in the engine compartment at the top of the firewall on a Fiat 124 Spider! I looked at it and thought, how in the world is that thing possibly pumping any fuel.
 
#34 ·
If you want electric pump and can not mount it below the tank a in tank pump is your best option. You may be able to find an entire TBI tank that fits your application.
These pumps last for years. I had one running over 20 years 300k still making good fuel pressure feeding a tbi unit.

You do need to drop your tank and install new straps. But as far as keeping the things cool they can run the fuel up to the regulatior and back all day long. They can do this while staying cooler and quieter then many inline pumps.

Maybe some model specific forum somewhere knows of a Tbi tank that will swap in with minimum modifications.
 
#35 ·
Good luck with your electric fuel pump and hope you can get it working well and not have any issues. I ran a mechanical fuel pump on my small block chevy for ten plus years with a dead head system and no issues ever with fuel boiling or vapor lock what so ever regardless of how hot it got outside and fuel pressure always was fine at 6 psi.

Last year I hooked up a holley electric pump and forget what color as they have a red and a blue but mine is the one that does not require a fuel regulator and maxes out at 6 psi so they say but I had it bolted on my frame as close to my tank as possible and it would suck a tiny bit through the line starting off then it went down to the fuel filter then to the pump and it would then gravity feed and then run all the way to my carb.

At first it was ok but as the summer heat got hotter I then started to loose fuel pressure. It would start off at 6 psi then after it would get so hot it would slowly drop to 2 to 3 psi at the most and even though it would still run ok for how I drive it still can't run in all conditions with that low of a fuel pressure and then for the first time ever in my life time after I shut my truck off I had fuel boiling in my fuel bowls.

I did not get vapor lock though but the fuel boiling became an issue as it sat when I was done driving for the day it would not boil enough to drip out of my boosters it would evaporate and my fuel bowls would almost be empty after sitting for three days. I then tried to install a phenolic one inch spacer and it still boiled fuel after running it and still loose fuel pressure and my underhood temperatures was pretty hot all the time I owned the truck since its pretty compact in there but all my fuel lines were away from my exhaust.

So earlier this year at the end of spring time in early May I started to have my fuel pump loose pressure as always but then it would start to get so bad that my pump would kit working and loose pressure all together and left my truck quitting on me and had to wait a while before I could start driving it again so it could get some fuel pressure back after it my hunderhood temperatures cooled down enough. I got home after a 5 mile drive through town and it died.

I was done with that and went back to my mechanical fuel pump and then I installed a holley billet fuel pressure regulator with a built in return line and it got rid of my loosing fuel pressure issue and I also have no longer shown issues of any fuel boiling after shutting it off even though its still pretty under my hood. I also installed a cowl hood so it could vent more heat out as well.

I live in Ohio and from 2017 on back I never had any issues with fuel boiling or anything close to it but since 2018 I have not changed anything before all these issues started and I think they have changed the fuel formula even more because of EPA stuff and the fuel boils even at lower temperatures now and don't work as good with carbureted vehicles like in the past since they have gone to fuel injection and now direct injection its getting harder and harder to keep the old school stuff going without having to do a lot of tricks and parts to keep them running with out issues.

My next step just to help is wrap some heat wrap around my fuel lines under my hood as best as I can and the return line is almost a necessity with today's fuels and how picky they are.
 
#36 · (Edited)
Eric, you're into the classic situation I harp on to which it seems no one pays attention too. Including the OP!

The self regulation Holley pump and other makers of these type pumps use an internal bypass.

With internal bypass there is no way for the bypassed fuel to cool. No length of line and certainly no ideal situation of retuning to the tank.

The fuel goes through the pumping element, gains pressure and of course heat. The amount not needed by the engine is bypassed within the pump to be delivered back at the intake side where it goes into the pumping element to be pressurized and heated again.

For some portion of the pumped fuel this process loop just keeps repeating. Obviously the less fuel the engine is consuming as at idle through cruise the greater is the amount of fuel that is making this bypass loop inside the pump. Which of course is heating all the delivered output whether that is the fraction that gets to the carburetor or has been bypassed.

The solutions:

1. A pump with a control module that reads pressure and either modulates pump speed through voltage reduction which results heating the pump motor or uses Rocket Science, Pulse Width Modulation to rapidly cycle the motor through off and on cycles of varying length to maintain the desired pressure without frying the motor's windings.

2. Or to use a remote bypass regulator mounted as close to the end user by it carburetor or fuel injection. This does several favorable things:

a. the pressure everywhere is the same as the regulated setting. This alone helps reduce heating the pumped fuel.

b. a return line that has feet of distance allows pump heated fuel some cooling so even if the fuel is looped back to the pump inlet it has some time and distance to bleed heat before reentering the pump.

c. the best return situation is back into the tank. This provides the time and distance advantages of part "b." plus the dilution into the remaining fuel to both allow cooling and any trapped vapors to bleed out into the tank to either condense to liquid or to vent off.

Part "2." in general and section "c." in particular is my favored go to system in this age of highly volitile fuel, it solves about 99 percent of these problems with fuel vaporizing inside the delivery system.

Since fuel loss from carburetors after shut down is also a problem I put this system on a manual "Prime" switch that allows the pump to be turned on before bringing the elctrical system up with the ignition key switch. This provides some time to fill the bowls before commencing the start sequence. Once commencing the start sequence on the key switch, I shut off the pump prime switch. I use a toggle with a safety cover, one whack and it's off.

No difficulty, pump the throttle a couple times, crank it over it fires like it's got injection. Pretty much fits my KISS principle of keeping it simple as possible, easily repairable, and dependable.

Bogie

Bogie
 
#37 · (Edited)
Bogie I might be misunderstanding what your saying and please forgive me if I do as I am not an expert as I don't have the years of experience like you and others as I am only 43 years old and have not come on to my own in doing things for myself until around 2009 as everything before that time I had no clue about hardly anything except changing fluids and checking levels and that is about it. I did not even know hardly anything about adjusting and tuning carbs let alone anything fuel system related. Its only in the last year that I have been reading on things and from others on here and also doing my first hookup of a return line.

I run my main line to the mechanical pump then run it out to my holley fuel pressure regulator which has the built in return line which is 5/16 and run it all the way back to my tank on the return port on my fuel sending unit. I have never had any more fuel related problems since doing this with my mechanical pump and I keep excellent pressure at all times and I also no longer have any fuel boiling issues like I did before when it was setup as a dead head system with the electric fuel pump. And I also don't mean anything negative towards you so if it sounds like I do I don't as sometimes I am not good with words and mean no harm or disrespect in anyway shape or form.

The electric fuel pump went out before I could even hook up my return line and got the regulator that has the return feature. Maybe its not the traditional way of hooking up one but its working for me and I would not know a different way of hooking up so please forgive me and I have seen a diagram before of a different way but my fuel is no longer getting overly hot like it did before since I have the return setup like it currently is.

Sorry for my lack of knowledge but I am wanting to learn of other ways but I have not seen them posted or I might have missed that and might have lost or forgot to write this information down to add to my other notes that I write off of these forums that may be helpful for future issues. I no longer use an electric fuel pump and only use a mechanical pump since my electric one went out and I had enough of it.
 
#38 ·
One thing I considered doing, since I'm near the tank anyway is to install a tee coming off the discharge of the pump and run a 1/4" line to the vent on the filler neck. That way some fuel is constantly be recirculated in the system even if it's not from the engine compartment. The downside is I'm going to loose a bit of fuel pressure but this pump is supposed to be rated for twice the HP my engine is making.

I don't think this Carboyle pump I plan on installing has any internal bypass mechanism inside it like the Holley pumps.

I have actually had better luck dead heading electric pumps than using a recirculating line.

Years ago I had a Fiat 124 Spider (still own one today) that came with electronic fuel injection. The system was botched so I had these dual Weber IDFs I wanted to try out.

I replaced the fuel injected pump with one of those Facet cube pumps. I thought it would be a good idea to use the fuel return line since there was already one on the car.

Every now and then the car would just act like it was running out of fuel and stall. If I let it sit for about 30 seconds, it would run fine.

I installed a pressure regulator before the carburetors set at 3 PSI and blocked off the return line going back to the pump. After that I never had any problems.

I'm wondering if more fuel was being diverted back to the tank than to the carburetors?
 
#39 ·
Back on post #3 I suggested using T ing a line into the FILL Neck. Pull the neck drill a hole and weld in a 3/8 tube. Reinstall neck then run line to it.

You dont want to use your vent line because fuel can pool in a area of hose on top of tank blocking the vent which will cause filling problems or if stored could cake and block that line.

Tank, filter, pump, filter, regulatior, then back to the tank. System works. You can use your old tanks feed line as the return line. You just need to pull the sock off. Just try to point the return away from the feed so you do not aerate the fuel.
 
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