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AK260

Electric fuel pumps

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Inspired by Captain Obvious, I thought I would go out for a last tango last night before they salt the roads.
 
As it happens less than 1.5 miles in, accelerating off a roundabout at 2.5-3k rpm, the car suddenly lost power with afr at 18+ and struggled back to idling after pulling over. I suspect the diaphragm on my good mech pump has also started to go in the same way the other one did. Last time this happened I swapped the pump on the side of the road and it’s been perfect until now.
 
I do have a NOS diaphragm, but I wonder if that will go too at some point.
 
 
So I am looking at installing a tandem electric pump or possibly just going electric full stop.
 
There are a number of options available but I’m truly confused what is best for performance and reliability.
 
Planning on staying on the SUs so I need something capable of 3.5 psi or more and a pressure regulator. Or are there self regulating pumps that stay at SU / carb safe pressures?
 
I like the idea of the K&N and it’s small foot print. What I’ve read says it’s quiet in operation too:
 
 
https://www.knfilters.co.uk/81-0401-fuel-pump
317b4189fdd6caaee18a91561fc3e241.jpg&key=dea722a1a25a83f86d32c261d00a467e19581ae0224984d6bfd7fdacf3e678f5
 
The NISMO was a nice option a few months ago when it was £80 on amazon but has now shot up to £180+ with import duties. So no longer as interesting.
 
f2f9d20d999a2cd61caeee6565629264.jpg&key=36165de034a9d12ba64cb33f83795c50e03aff9d8bbd7a885e50163a8d42796e


Then there are NISMO “looking” ones on eBay for peanuts. I can only assume these are cheapo Chinese items that will fail quickly. Or am I being bigoted?
68c7303e979262853d2e9101c2132b5a.jpg

 
The Facet Silver top: relatively low pressure and time honoured use on Zs makes it an attractive option. I also like the Malpalsi fuel filter / regulator that would fit well where the current fuel filter resides - this eBay listing seems like a good combo - do you agree? Or shall I be going red top and pressure regulator? Wouldn’t it be a waste to have more pressure that I can’t realistically use with carbs?
 
https://www.ebay.co.uk/itm/Facet-Silver-Top-Fuel-Pump-Malpassi-Filter-King-Regulator-Kit-up-to-200bhp-/121064855696?_trksid=p2349624.m46890.l49292
 
 
0205b96782ac85c12ff13c42454cd403.jpg&key=b83b528723c0487604da7d717f19c41a457c9910670aca81d54560617a25722a
 
 
Any thoughts or experiences with these or other pumps would be greatly appreciated.

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3 hours ago, AK260 said:

I can only assume these are cheapo Chinese items that will fail quickly. Or am I being bigoted?

I would hazard a guess that all 4 of those pumps were made in China, the only one I wouldn't buy is the K&N, it looks like a fish tank pump.

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I've got very little direct experience with the whole fuel pump thing, but since I'm planning some evil carb mods with my new motor, I'm going to have to get involved with this as well. And with that in mind, I'll be watching your progress.

So one thing to watch for is... Does the pump require some minimum amount of fuel to flow in order to keep the pump itself cool? If so, you must use a bypass style regulator and shunt excess fuel back to the tank. However, if the pump doesn't require cooling like that and is designed to be able to constantly push against a "mostly closed door", then you could get away with a dead-headed arrangement.

I've heard with my own ears two of the aftermarket pumps and they were loud. I'll see if I can figure out what they were. My buddy put one in his car and the drone made him crazy. He replaced it with another brand and it still drones, but not as bad as the first one. Maybe @GGRIII come in and tell us what brands he used.

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What amazes me about many of these aftermarket pumps is how often they undershoot their rated pressure. I put a fuel pressure gauge on a 240Z with the Facet labelled version of the K&N pump. The mechanical fuel pump was bypassed.spacer.pngspacer.png My gauge was reading about 2 PSI. (0-15 scale)

Facet Pump.jpg

In my own experience, I had good results with a Holley Blue and a Holley 12-804 regulator, eliminating the stock rail. However, that is because I have an engine with a Maxima head that does not have the window open for the mechanical fuel pump.

 

Edited by SteveJ
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One thing I feel like I should mention first - there is a filter IN THE FUEL TANK.  At least there was on mine (early 74)  If your inlet in the tank is restricted, you can't expect the pump to do much about that. They want to push the fuel not pull it. I had Captain obvious modify an adjustable non-bypass regulator to make it an adjustable bypass regulator. If you go that route you should eliminate the restriction orifice in the stock fuel rail. So that sums up the system as a whole.  Pump back by the fuel tank, internal filter removed from the tank, pre-filter before the pump, modified fuel rail with the restriction removed, and a bypass regulator that I keep at about 2psi. I isolated the pumps with rubber grommets and such.  The Holley Red was easily heard over an MSA twice pipes exhaust!  So I switched to a Carter P4070 better, but still loud.  Both of these pumps are overkill for a stock-ish motor IMHO.  I too am looking to get a lesser pump that isn't as freakin noisy as the two previously mentioned.  I guess on the plus side I always know if the fuel pump has power!

 

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Up until I swapped to EFI last year, I was using a BMW diesel 4 bar pump and an Aeromotive bypass regulator. Now I'm on EFI, I'm using a BMW diesel 4 bar pump and an Aeromotive bypass regulator 🙂

The fuel pump has done about 200,000 miles, so I think it's good on the reliability front. 

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When I was looking at high pressure pump options I found that older Ford trucks used two pumps.  One to pull from the tanks and one to pressurize the EFI system.  The high pressure pump was mounted up under the driver's side firewall, and the supply pump was in the tank I think, or close to it.  I don't know the specs on the supply pump but I'd assume it would be low pressure.  Might be worth digging in to.

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2 hours ago, GGRIII said:

One thing I feel like I should mention first - there is a filter IN THE FUEL TANK.  At least there was on mine (early 74)  If your inlet in the tank is restricted, you can't expect the pump to do much about that. They want to push the fuel not pull it. I had Captain obvious modify an adjustable non-bypass regulator to make it an adjustable bypass regulator. If you go that route you should eliminate the restriction orifice in the stock fuel rail. So that sums up the system as a whole.  Pump back by the fuel tank, internal filter removed from the tank, pre-filter before the pump, modified fuel rail with the restriction removed, and a bypass regulator that I keep at about 2psi. I isolated the pumps with rubber grommets and such.  The Holley Red was easily heard over an MSA twice pipes exhaust!  So I switched to a Carter P4070 better, but still loud.  Both of these pumps are overkill for a stock-ish motor IMHO.  I too am looking to get a lesser pump that isn't as freakin noisy as the two previously mentioned.  I guess on the plus side I always know if the fuel pump has power!

 

I don't think that was a stock fuel filter in the tank. I can't find any mention of it in the parts manual or FSM.

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It sticks in my mind that people also have used an RX7 electric fuel pump on a 240Z with good results, that may be worth searching and reading about unless anyone here has first hand experience.

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I own a 1st gen. RX7. The elec. pump in it is virtually silent. Many z owners over the years have reported using the 1st gen. RX7 pumps (not sure about later gens) with satisfactory results.

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Why would anyone not use it?  Seems to meet the needs, and there are options.

https://www.rockauto.com/en/catalog/mazda,1979,rx-7,1.1l+r2,1192227,fuel+&+air,fuel+pump,6256

It's weird that there is no option for an electric pump around the internet even though the 240Z's are wired for it.  It's a market that needs to be addressed.  Opportunity missed.

https://www.rockauto.com/en/catalog/nissan,1973,240z,2.4l+l6,1209170,fuel+&+air,fuel+pump,6256

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Thank you all for giving me lots to absorb and think about!

One of my main requirements is a quiet pump - can’t stand the loud buzzing on some classics I’ve seen / heard running elec pumps!

Interesting also that the K&N one appears under different brands - good to know it worked well.

There is made in China and made in China - I guess the difference is quality control by certain brands and what can come out of the side of the factory without oversight. I received some AirPods I hadn’t ordered (long story), the box said price was $25 they were utterly identical to Apple ones - worked great for 12 hours!!!

The BMW / RX7 pumps I like the idea of and will defo research more.

I had no idea there was a fuel filter in the tank!! Being a ‘77 I’m not sure if mine has one or not. How on earth did CO remove it? When I put a camera into my tank this summer, I saw that the intake on mine was behind the baffle - did you take the tank apart?

I was planning on leaving the fuel rail alone and setting the regulator to c. 2-3 bar to allow headroom for any pressure creep. Is that a bad idea?

As for the facet pump and Malpassi regulator combo I found on eBay, Demon Tweaks in the UK is doing both for 1/3 less.

It is perplexing why two pumps would fail in less than 500 miles of each other. I am wondering if the lining inside the tank is coming off and causing an intermittent blockage? Will take filter and one of the pumps apart this week and have a closer look. I worry that if this is the case, it will also cause issues with an electric pump.




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I would avoid the `carter p4070` model in particular if you like to not hear the pump. I think anything in a similar style will give you the same problem I have, which is LOADS of cabin noise, i cant figure out how to dampen it. However I've used it since i got the car, never had an issue with it, so its reliability is nice.

I like the Facet one, I would opt for that for easier install with the OEM bracket for the electronic fuel pumps.

Iif that is also noisy then something like the Rx7 one you posted should work, my buddy uses one similar in his classic mini and his buyeye sprite, I never notice the noise they make.

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Right then chaps and chapesses (the latter clearly referring to Captain Obvious - the big tart playing with his shiny bits)!

I took apart the Aussie pump I bought at a vast expense a few years back - this was the one that I thought had initially failed and swapped out for the original one on the side of the road. The diaphragm is utterly perfect and frankly I was impressed by the quality / thickness of it. The valves seal and release well and I can’t blow or suck through them in the wrong direction

I gave it a suck and blow test with the vacuum gauge: it’s pulling 5-8 inhg and pushing 2.5-5 psi depending on how gently or vigorously it’s stroked. Here’s a video of the test in case anyone is interested in how well the mech pump, can blow ...




(Forgive the staccato speech, weeks of insomnia is finally getting to me!)

So it seems I need to turn my attention to a fuel blockage. I am getting black fish swimming around inside the filter and given that I replaced the fuel lines for alu with only 20cm of fresh rubber used, I am strongly leaning toward the POR15 treatment letting go. Some of it wasn’t flushed out properly by the PO and I wonder if there are lumps that aren’t fully set coming though? See the area where the float is sitting. You can see a black “eel” next to it before I flushed the tank. Also you can see a crater where the POR treatment wasn’t properly flushed out and has set.

07955c16799b472b7e54cb57c41c161b.plist&key=15090d478896ffe312371eb1caa643532cf36bebb486d0942efe711b9fafe1b4

I would like to point out the soldierly self restraint exercised on a post so rife with innuendos! (“Oh matron!” You have to be old enough to know where that comes from)!
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In my early 74 there was a small perforated can that was over the end of the pickup tube.  It dislodged when I was rattling bolts around in the tank to remove as much crud out of the tank as possible...  I suppose it could have come off of something other than the pickup - I was assuming it came off of the pickup.  I wish I had saved it so I could post a picture.

 

Edited by GGRIII
clarification

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I found a reference to a 76 fuel tank that describes a fine mesh screen around the base of the canister that the pickup and return line are in.  I thought that the 240Z inlet lines had a metal "sock" on the end of the line.  Basically like a metal fishnet.  Can't find any cut open 240Z pictures though.

https://forums.hybridz.org/topic/96315-por-15-fuel-tank-repair-question/?do=findComment&comment=910896

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I guess the take away is that I think there have been more than one person that has had 'fuel pump' issues that may indeed have been restricted pickup tube issues... Easy thing to check.  The next pump I was going to try is a Carter P90091 or P60430.  Any thoughts on this style on pump?

Anybody want a Holly Red? If I find something else, anybody want a Carter P4070? 

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8 minutes ago, GGRIII said:If I find something else, anybody want a Carter P4070? 

There are two of those on my race car, my Dodge Ram has a version of the Carter pump to send fuel to the injector pump (Cummins diesel), and  I built a fuel transfer cart that has a Carter pump.

Mount them with rubber isolators and the noise is much lower.

 

 

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12 hours ago, AK260 said:

Right then chaps and chapesses (the latter clearly referring to Captain Obvious - the big tart playing with his shiny bits)!

"Who? Me?" He asks, sounding a little startled. As if he was interrupted doing something he ought not to be doing...

P1180008.JPG

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The carter 4070 in my car heard me talking trash about it and decided to blow a fuse on the way home from getting coffee. No idea why it would do that, first time its happened. Luckily i found a fuse buried under the carpets, good think i dont clean eh?

In all seriousness it was SO much more quiet in the cabin after the pump died, almost makes me want to get a replace it. @Racer X what rubber isolaters? the small ones that come with it, happen to have a picture of the setup?

Edited by heyitsrama
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The carter 4070 in my car heard me talking trash about it and decided to blow a fuse on the way home from getting coffee. No idea why it would do that, first time its happened. Luckily i found a fuse buried under the carpets, good think i dont clean eh?
In all seriousness it was SO much more quiet in the cabin after the pump died, almost makes me want to get a replace it. [mention=31874]Racer X[/mention] what rubber isolaters? the small ones that come with it, happen to have a picture of the setup?


Gosh! Sorry to hear that, but at least it proved a point. ;)

At present I’m planning on swapping the feed and return lines over at the tank end to prove it’s the pickup that’s my issue.

However, when / if I do an elec pump, I am planning to ditch the stock bracket designed for the job and make my own anechoic chamber for it - read, metal “box” with screw on lid, lined with 10mm closed cell foam sound insulation and rubber isolation feet like these ...


https://www.ebay.co.uk/itm/Rubber-Shock-Absorber-Rubber-Vibration-Isolator-Silentblock-Mounts-M6x20x15mm-/383835310627?_trksid=p2349624.m46890.l49292

182203cda2a7fe366ef591c9e5bbfe55.jpg&key=5532a18440cee672096358de995e804c838685b026ba8465d0dcb355e539a9b3

I truly despise noisy fuel pump sounds!!!!

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11 hours ago, heyitsrama said:

 @Racer X what rubber isolaters? the small ones that come with it, happen to have a picture of the setup?

The isolators look like these:

image.jpeg
(not my picture)

image.jpeg

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3 hours ago, Racer X said:

The isolators look like these:

image.jpeg
(not my picture)

 

Do you happen to have a source for these (a link would be awesome!)?

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