External fuel pump screaming/loosing pressure

[Ether]

Has happened twice now. New build, probably 100ish miles on it.

1/2 tank of gas, pump is making a steady high pitched sound. Fuel pressure is all over the place from 10-20’s/30’s

Edelbrock efi, single E2000 style frame mounted pump pulling from stock pickup (new, new stock tank)

Seems to do this after running for 30+ minutes. Turning off/resting seemed to remedy. I thought a non vented gas cap was the culprit initially.

My return line from the fuel pressure regulator goes to one of the vent lines on the tank. The other is capped off.

Cavitation? Dying FP? Overheating?

I have a spare pump to try, will probably start there since that is easy-ish to try.


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[lars]

A high pitched whining does probably mean that the pump is being starved. Start with the easy stuff. Check the fuel filter. I have a 100 micron filter upstream of the pump, 10 micron filter downstream. I have had crap in the tank partially clog the upstream filter. Also check fuel lines. Even thought I plumbed my system with EFI compatible hose, I had pieces in the circuits from both tanks collapse and start sloughing off the hose liner. Probably due to the stuff they sell here in California that only loosely resembles gasoline. Where does the pump live?

 

[nvrstuk]

Also could have a leak in the connections btw the pump and the pickup in the tank (sucking air).

 

[Dylan_Shaffer]

Sounds like inadequate tank venting to me. I’ve found vented gas caps don’t always provide enough airflow to keep up. Id run a dedicated fuel tank breather to the vent line that’s capped off, I did the same when I went to efi.

 

[Ether]

5/24 Update: drove it 1hr to work, issue started about 25min into the drive. Pulled over, turned it off. Pump, primary filter, and return line (rubber) are all cool to the touch. 99% sure my issue is aeration in the tank, and/or vapor lock in the fuel rail (just because how hot it was to touch yesterday). Stopped one more time, again at about 20min and runs perfect after sitting for just 4-5min.

I think I will try to move the return line, or add a hose to the return on the inside of the tank…

Something like this:

https://www.holley.com/products/plumbing_an_fittings_and_hose/fuel_system_components/fuel_cell_bulkhead_fittings/parts/166025ERL

Or this:

Amazon.com

Or?


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[76Broncofromhell]

High pressure pumps have a smaller gerotor section that spins faster to create more even pressure and still move the proper volume. They produce hardly any vacuum - and are prone to cavitation if not completely immersed in fuel. This differs from a low pressure pump which have large voids that are created when each gear section makes a rotation. These larger voids produce more vacuum and thus do a better job of pulling fuel. This is why LP pumps (like the Carter P4070) have no issue pulling fuel from the tank with a stock configuration and why high pressure pumps are almost always submerged in-tank pumps.

It's important to remember that gasoline has about 1/5 the surface tension of water meaning it's much harder to pull through a tube - which if you've ever tried siphoning water vs gasoline you would understand how much less water you get in your mouth than gas. Every OEM that ran an external high pressure pump ran an internal low pressure feeders to quell the vapor lock issue.

The point of all that is almost all high pressure only external pumps will experience vapor lock. It's not a byproduct of how your tank is vented - it's how the pump is designed. The E2000 specifically had a carb pusher pump matched to the flow rate to feed it because any loss in siphon from the sending unit will cause cavitation :

https://www.oreillyauto.com/detail/c/precision-fuel-pumps/fuel-delivery/fuel-pumps---tanks/fuel-pump/fuel-pump/83db8e3f0135/precision-fuel-pump/pfp0/e16270/v/a/5300/automotive-truck-1988-ford-f-150?q=fuel+pump&pos=5

TL;DR get a Carter P4070 to push to this pump or convert to an in-tank.

 

[Timmy390]

I've got 2 E2000's servicing 2 different EFI's and they work perfectly with stock carb tanks on both. One returns to the filler neck vent hose (Bronco 351W) and the other returns to the tank via the stock return (Samurai 1.6L and EFI from a Sidekick). Both are mounted on crossmembers middle of the tank high right next to the tank. both have a cheap inline filter pre pump and EFI filter post pump. I've ran both on and off road (not rock climbing just some hills and logging roads and through skidding areas at our hunting camp) and neither has skipped a beat even on the hottest of hot summer days here in AR.

I'm not saying it's not the pump but many many EFI applications are running a single E2000 style pump with no issues.

Where did you get the pump? I got mine at Oreillys and the other from Summit. Maybe you got a knockoff? Like the fake Motorcraft sparkplugs I bought a couple years back.....

Tim

 

[Ether]

I've got 2 E2000's servicing 2 different EFI's and they work perfectly with stock carb tanks on both. One returns to the filler neck vent hose (Bronco 351W) and the other returns to the tank via the stock return (Samurai 1.6L and EFI from a Sidekick). Both are mounted on crossmembers middle of the tank high right next to the tank. both have a cheap inline filter pre pump and EFI filter post pump. I've ran both on and off road (not rock climbing just some hills and logging roads and through skidding areas at our hunting camp) and neither has skipped a beat even on the hottest of hot summer days here in AR.

I'm not saying it's not the pump but many many EFI applications are running a single E2000 style pump with no issues.

Where did you get the pump? I got mine at Oreillys and the other from Summit. Maybe you got a knockoff? Like the fake Motorcraft sparkplugs I bought a couple years back.....

Tim

It's actually the pump that came with a Holley Sniper setup, that I then sold and kept the pump/filter for my edelbrock setup. I have no idea how much it was used or how before I got it.

I'm leaning toward an in tank retrofit, but may try another pump and different pre-filter. I also need to pull the stock sending unit and look at the filter/sock just to check it. The tank and sending unit are newish, and still look new.

 

[Ether]

Swapped out the "holley" pump for the one pictured. The one I removed is not holley branded. Drove around tonight, 45-70mph, no issues. But I still plan to mod the sender and put a Walbro 255 in the tank, also move the return or put a hose on the current vent/return down into the bottom of the tank

 

[Yeller]

I’ve done probably a 100 just like @Timmy390 describes and none have had any issues, my personal stuff gets used in dumb ways, never misses a beat till u try to drag the door handles on the ground and am under a 1/4 tank

I would lean towards the return being to a vent line as a potential issue. This time of year, you will never get vacuum in a fuel tank except maybe early in the morning, it will be making pressure

 

[Ether]

Crusty pickup/sender before clean up and mods.


“Final” update….

I had swapped to a different frame mounted pump, same specs. Seemed better but eventually had same issues.

Decided to order all the parts to do an in tank pump, pump/sock, electrical bulkhead fittings. Also parts to move return to the 5/8” vent hose.

Then, When I pulled the pickup/sender the oem style pickup filter was very brown….and full of crap.

Looked in the tank, pretty crusty. So I pulled the tank and filled with a gallon of evaporust/ handful of screws. Then sealed it and paid my 10yr old to flip it around every 30min all day Saturday haha

Reassembled my in-tank setup, replaced the float with a plastic one (Heep CJ application). Rewired/plumbed everything and it runs awesome!

So ultimately the pump was being starved, and I believe the frame mounted setup would have been fine.

Floaty no float…

Fuel pump set up built/finalized. Barely enough room for the bulkhead fittings.

Completed. Had to trim pickup close to the bend.

Pump was pulling fuel through this 100micron filter!

Dang. Looks like charcoal.

Clean


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[73azbronco]

algae in ethanol fuel maybe?

 

[Scott McKelvey]

Crusty pickup/sender before clean up and mods.


“Final” update….

I had swapped to a different frame mounted pump, same specs. Seemed better but eventually had same issues.

Decided to order all the parts to do an in tank pump, pump/sock, electrical bulkhead fittings. Also parts to move return to the 5/8” vent hose.

Then, When I pulled the pickup/sender the oem style pickup filter was very brown….and full of crap.

Looked in the tank, pretty crusty. So I pulled the tank and filled with a gallon of evaporust/ handful of screws. Then sealed it and paid my 10yr old to flip it around every 30min all day Saturday haha

Reassembled my in-tank setup, replaced the float with a plastic one (Heep CJ application). Rewired/plumbed everything and it runs awesome!

So ultimately the pump was being starved, and I believe the frame mounted setup would have been fine.

Floaty no float…

Fuel pump set up built/finalized. Barely enough room for the bulkhead fittings.

Completed. Had to trim pickup close to the bend.

Pump was pulling fuel through this 100micron filter!

Dang. Looks like charcoal.

Clean


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By chance do you have parts list for what you used?

And how's it working after 6months or so?

I'm in need of an efi pump solution and yours is an interesting option.

 

[Ether]

Working great!

Let me see if I can get the parts list together. I believe it was done before here on CB.


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[Ether]

Here are screenshots of the parts I ordered. Let me know if you have other questions!

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[Gsav69]

Here are screenshots of the parts I ordered. Let me know if you have other questions!

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Just found this while i was planning an intank budget setup for a sniper efi on a 170. Bringing me back to my import drag racing days. What did you do in terms fuel lines? Thx for all this. U may have save me the r&d time.

 

[Ether]

Rubber transition lines to AN fittings and AN hoses.

 

[Gsav69]

Rubber transition lines to AN fittings and AN hoses.

Did you consider adding a bigger aquasock/filter to the bottom? Did u use 5/16 or 3/8 line? Any changes or advice around the vent? I appreciate the inspiration and r&d bud..gonna order stuff up today and would like to confirm ur happiness and success before going down this road if a new tank is in inevitably in my future.

 

[ntsqd]

If you are going to use anything AN, JIC or similar then -5 sized adapters (5/16") and hose ends are limited in selection and rare to non-existent. Go all -6 (3/8") and save yourself a bunch of pain.

When the plan is a supply and a return line I buy the fittings to color code the systems. Supply might get the blue & red, while the return system gets all black hose ends & fittings.

 

[Gsav69]

If you are going to use anything AN, JIC or similar then -5 sized adapters (5/16") and hose ends are limited in selection and rare to non-existent. Go all -6 (3/8") and save yourself a bunch of pain.

When the plan is a supply and a return line I buy the fittings to color code the systems. Supply might get the blue & red, while the return system gets all black hose ends & fittings.

Thank you. Im doing this on a 170 and ive seen an argument 3/8 is overkill. Appreciate the thoughts and advice. Pumping the brakes on my order as a result.