Electric fuel pump question

[dave`12]

My truck was running really low on gas tonite (yeah, stupid me). On the way to the gas station, it shut off, started once, then that was it.

I cannot hear the electric fuel pump, so I know it's not working.

I'm curious if anyone knows if these things have auto shut offs when there is not gas, perhaps to protect the pump? Seems fishy that the pump picked that time to die.

It's a cheap discount auto electric fuel pump (yeah, stupid me).

It's late at night or I would test my theory, so I thought, why not ask the experts before messing with it later.

Thanx

[truckster]

Is it an in-line or in-tank pump? Have you checked fuse and relay? Those are the places I would start.

[Ol Blue K20]

What year truck? What fuel pump set up?

[rpmerf]

Pumps are cooled by the gasoline running through them. Running low on gas does not help the life of pump.

Some inline pumps can push fine but have trouble pulling. This can make it easy to burn up the pump.

As truckster said, check electrical first. Get your test light or volt meter and make sure it is getting power to the pump. Check it at the pump. Check the ground for the pump.

Might try tapping the side of the pump with a wrench or screwdriver handle to see if that can convince it to work. Just like with a bad starter.

[dave`12]

thanx for replies. as I said, it's a cheap discount auto pump. I mounted it in a box under the floor.

the fuse is good, and power to the fuse, but I didn't get time to get underneath and open the box to check it out.

so, I guess this pump probably did not autoshut off; but rather burned up with no fuel or it is a coincidence that it went bad when my fuel gauge is very low. I consider it highly unlikely that the wires on the pump are bad, I was very careful to get it right and waterproofed.

hope to get time over the weekend to get it straight.

taking recommendations on an electric inline pump that will be reliable.

thanx again.

[dmjlambert]

How long after the truck ran out of fuel and quit did you keep the pump running dry?

[dave`12]

Hello, dmjlambert! Good to "see" you again.

To answer your question; the engine is way to loud to hear the pump while it is running. The engine faltered, died, I restarted, went about 60 feet and died again.

It was then that I noticed I did not hear the pump, so the short answer is "I have no idea."

[truckster]

rpmerf mentioned tapping the pump. That's an easy fix if it works, and I've had pumps run for years after they seemed to fail just from doing that.

If the pump is toast, I've had good luck with Carter pumps. Stewart-Warner pumps are good too, but they tend to be a little more expensive.

[firedemon]

if its at all possible run a return line and regulator if you can it helps with the heat . cooler running pumps last lots longer

[dmjlambert]

Hit it with a hammer and see if it straightens out the attitude. Now that your pump is questionable, can you convert to a mechanical pump?

[dave`12]

Sorry long delay, I've been doing some home upgrades and no time for truck.

Tapping the fuel pump gets it to turn on and the truck will run, but never lasts more than a minute or 2. I think I'm going to try a better electric. A couple of questions if I may:

1. Should I use rubber mounts for vibration? I didn't before.

2. I've mounted it under the floor board in a box. After taking off the box, I see no evidence that water has got in, everything still looks shiny and clean. Heck, I don't even drive in rain. Still, do you think I should relocate the new pump, perhaps to the firewall?

Opinions on this as a new pump?

https://www.summitracing.com/parts/c...stionsanswers/


Thanx!

[GASoline71]

Originally Posted by dave`12

it's a cheap discount auto pump.

I think this is your main problem.

I've been eyballing the inline pumps made by Walbro. They are pushers, so need to be installed close to the tank. Will need a regulator also.

Gary

[geezer#99]

Electric pump in a box!
No wonder it quit.
They run hot!
Need ventilation.
A shield maybe if needed.
What carb you running?

[GASoline71]

Good eye geezer... just went back and reread that.

Gary

[dave`12]

The box is a plastic electric box 10" x 3" and 5" deepm. It is vented, and the pump is small, no bigger than a inline fuel filter. It's perhaps 2 inches from the bottom and 2" front and rear. Plenty of room for air circulation. Mounted to the floorboard about 6 inches from the muffler, but the frame is between them.

If you look at this post, part way down I have a pic from when I changed over my alternator. You can see the black box by the battery in the post with 3 pics.

http://www.67-72chevytrucks.com/vboa...=763180&page=3

Still think it got hot?

I've got a holley 625 street demon, only about 6 months old.

[dave`12]

The box is a plastic electric box 10" x 3" and 5" deep. It is vented, and the pump is small, no bigger than a inline fuel filter. It's perhaps 2 inches from the bottom and 2" front and rear. Plenty of room for air circulation. Mounted to the floorboard about 6 inches from the muffler, but the frame is between them.

Opinion on whether this is going to cause heat issues with a new pump?

thanx

[100%Chevy]

When you run out of gas and the in-tank filter sock is bad or clogged with trash,you won't get much gas thru it and if the trash gets in the pump,it will stop it from running.Will even cause it to burn up.
You have to have an in-line filter between the tank and pump.
So,when you replace it,don't forget the filter!
Mike.

[Andy4639]

Originally Posted by dave`12

The box is a plastic electric box 10" x 3" and 5" deep. It is vented, and the pump is small, no bigger than a inline fuel filter. It's perhaps 2 inches from the bottom and 2" front and rear. Plenty of room for air circulation. Mounted to the floorboard about 6 inches from the muffler, but the frame is between them.

Opinion on whether this is going to cause heat issues with a new pump?

thanx

The inline pumps I have seen are all air cooled so if the pumps get fresh air all the time it should be fine. I would make a rubber mounting ring for it also.
You can always put a small LED light in the dash area and tie into the 12 volt's at the pump itself so when it's running you know by the light.
Are run a fuel pressure switch into the cab to keep eye on fuel level.

[dmjlambert]

I recommend while you're working on fuel pump stuff anyway go ahead and add an oil pressure cutoff switch for the fuel pump. That way it won't run if the engine isn't running, and won't gush gas after a wreck.

[Andy4639]

Originally Posted by dmjlambert

I recommend while you're working on fuel pump stuff anyway go ahead and add an oil pressure cutoff switch for the fuel pump. That way it won't run if the engine isn't running, and won't gush gas after a wreck.

That would work nicely to.

[siggyfreud]

Since I saw mention of it I'd caution you away from mounting it on the firewall. One, if drag/track racing is in your future most won't allow it. Two, it just isn't a good idea to add a fuel source right on top of the barrier that is supposed to protect you in a fire . There is a reason they call it a firewall.

[dave`12]

Good advice all.

I'm still curious if you all think being that the box is good sized, that I can get away with where it is mounted (6 inches from muffler, but on the opposite side of the frame.

Prefer not to make any more holes than I have to in the truck.

[HO455]

Originally Posted by dave`12

The box is a plastic electric box 10" x 3" and 5" deep. It is vented, and the pump is small, no bigger than a inline fuel filter. It's perhaps 2 inches from the bottom and 2" front and rear. Plenty of room for air circulation. Mounted to the floorboard about 6 inches from the muffler, but the frame is between them.

Opinion on whether this is going to cause heat issues with a new pump?

thanx

As long as the vents are on the top and the bottom and the bottom ones below the pump itself there should be no problem. That will allow the air to circulate, as the hot air rises it will exit through the top and pull cooler air in the bottom. Natural convection cooling will work best with no holes in the sides.
I recommend the Revolution Electronics fuel pump controller or as others have said some kind of safety switch in case of an accident.

https://www.revolutionelectronics.com

As to your post about water in the box I would suspect condensation to be the culprit.

And your fuel pump from Summit should work as long as your engine is a basically stock 350 or smaller. The pump is designed for a much smaller engine and may not keep up with the the fuel demands of a health small block or a hard working big block.
And to help prevent future issues a 100 micron filter between the tank and pump is needed as well as a 30-40 micron filter before the carburetor if the inlet filter on the carburetor is missing.

[dave`12]

Thanx.

I've been on summit, but haven't found a pump that really seems great for me. Most are in tank. Has anyone here had good luck with an inline pump they would recommend?
I have a mostly stock 350 engine (holly carb), what flow/pressure do I need?

Let me clear some stuff up:
The box is vented top and bottom, not sides.
There was no water in the box.
I have an inline filter in front of the carb, I'm going to take the advice here and add another between the tank and the new pump.
Going to add rubber washers as well.
Still pondering the cut off switches. I have a cut off in the dash already.

And I guess from the responses that 6 inches away from the muffler on the other side of the frame should not be a problem...

[HO455]

What is your budget? I am currently running a Mallory 140 on my Burban. (Photo) They aren't cheap but rebuild kits are available. The Holley Red pump would be a good fit for your engine but I don't believe it falls in the "inline pump style" you are looking for. Pump comparison is somewhat difficult as many manufacturers purposely rate their pumps so comparison isn't apples to apples. But the rule of thumb is one gallon per minute for 10 horsepower at delivery pressure. So your Holley should require 6 psi and figure a basic 350 at 300 HP so in theory 30 GPM at 6 psi will suffice.
The pump from Summit you asked about is rated at 30 GPM but at zero psi or free flowing so there is no indicated GPM at pressure. Bends in the tubing, fitting, and filters in the system all add resistance and reduce the flow. Thus a pump on the edge of being large enough may come up short depending on these factors. So you always oversize a pump to compensate. Using the Holley Red pump rating as an example the 110 GPH will work with most street driven engines under about 400 HP with the average fuel lines and filters.

The link below is a document from the holley web site with good information. You can also go to their web site where they have a ton of videos with information and Holley advertising. The link will show up as blank hit refresh and it will download the PDF. (At least that's how it worked on my tablet.)


https://www.google.com/url?sa=t&sour...Sq9xuLmz5j9jMq