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TR4/4A Mechanical fuel pump vs electric

bammons

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I was going to rebuild my fuel pump but found that someone had "peened" some of the pieces in so I think I will just replace it. My question is for some time drivers on the reliability of the std mechanical fuel pump. If I am building a "driver" is the mechanical unit reliable over time? I would rather not add a electric unit unless I need to. So what is the experience of you out there who drive your cars? Is this one of those things that you just add a electric unit for insurance and peace of mind? What is the easiest and best unit (electric) to use and where do most of you place it (before the mechanical unit or after) and do most of you just eliminate the mechanical if you use the electric? Bruce Ammons
 

poolboy

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Some considertions should be given to the need for a pressure regulator or not with an electric and a method to shut off the electric in the event that the engine stops running yet the ignition switch happens to remain "ON"....some sort of accident for instance.
 

Geo Hahn

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I have found the mechanical pump to be very reliable once I went to using an original (rebuilt as needed) pump. The only failures I had were with after market pumps that cut a few corners in design (e.g. securing the valves and the rod for the lever).
 

glemon

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If you frequent MG or Healey boards you will see long discussions about SU electric pumps, alternatives to SU pumps, and wiring and plumbing two pumps so you can switch to the second if the first fails.

Absent empirical data relative reliability is a matter of opinion. I think the mechanical pumps are comparable or slightly better than the electric SU pumps, if you open the conversation up to aftermarket there are a lot of options and less experience, at least in the LBC world.

Electric pumps will give you a faster start after sitting a long time, as you don't have to crank the motor to turn the pump (I know hand prime is an option with original style too) And I believe for more radical modifications that require increased fuel flow electrics have been recommended too.
 
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bammons

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I used to have (a long time ago) a MGA with the electric pump and I remember the concern all the time about whether it would fail and then and probably now I bet most MG owners probabley carry a spare. So to clarify my post what I really want to know is should I put a electric unit in to insure realibility or am I fine with the std mechanical unit. My current unit was working when I got the car. When I opened it up to rebuild it I found the inlet and outlet valves to be "peened" in for what reason I don't know. So I could just drop the new diaphragm in and keep going that would keep me with the original unit but not all parts replaced. George you have indicated that maybe the current replacements are not as good?
 

charleyf

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I rebuild my mechanical pumps. If peened over I just replace what I can, namely the diaphragm. I have also found and purchased a few "older" pumps that have the one way valves held down with screws. Those are the keeper pumps!
If you learn to deal with the rear nut on the fuel pump with a 1/4" drive ratchet and short wobble extension, replacing the pump is not much of a problem.
 

Geo Hahn

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I have no recent experience with the current crop of reproduction pumps. They may be better than the ones I used 30+ years ago before sourcing original AC pumps.

I have seen some with the screw securing the valves as Charley mentioned... on the ones I saw there was a little metal piece butterfly-shaped held with one screw and clamping both valves in place.

Although the mechanical pump is reliable, I do carry an electric spare to get me home just because it can be fit up in minutes vs the time it would take to R&R the mechanical:

yx8A3Ae.jpg


Clips go to a ground and the white wire terminal of the coil. Hoses connect from the tank feed (5/16") to the carb feed (1/4").
 

Gliderman8

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I installed a low pressure Facet pump about 4 or 5 years ago and its been very reliable. In place of the original mechanical pump I installed a blank plate.
Electric pump is hooked up to a relay that senses rotation of the distributor which then energies the pump. Just recently (a few weeks ago) I installed an inertia switch with a small light in the cabin to let me know if the switch was tripped.
 

Gliderman8

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George... What kind of pump is that in the pic you posted?
Off topic --- Also, I hope the fire is not affecting you.
 

Geo Hahn

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Specifically this one (though I got it at Checker/O'Reillys):

https://www.amazon.com/Airtex-E8318-Electric-Fuel-Pump/dp/B000ZMYKE0

Also many similar pumps on eBay for about 11 bucks:

https://www.ebay.com/sch/i.html?_from=R40&_nkw=universal+12v+2.5+fuel+pump&_sacat=0&_sop=15

And yes, the Bighorn Fire is in our area. We were evacuated last week and since then it has continued to spread. We're hoping that crews can maintain a fire line at the highway as it will soon be across the road from us. All part of living in the mountains.
 

Gliderman8

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Specifically this one (though I got it at Checker/O'Reillys):

https://www.amazon.com/Airtex-E8318-Electric-Fuel-Pump/dp/B000ZMYKE0

Also many similar pumps on eBay for about 11 bucks:

https://www.ebay.com/sch/i.html?_from=R40&_nkw=universal+12v+2.5+fuel+pump&_sacat=0&_sop=15

And yes, the Bighorn Fire is in our area. We were evacuated last week and since then it has continued to spread. We're hoping that crews can maintain a fire line at the highway as it will soon be across the road from us. All part of living in the mountains.
Thanks for the info. Stay safe... rain would of course help in your area.
 

Harold

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I have installed the airtex electric fuel pump and regulator on 4 Nash Metros and a "safety switch" which cuts the electric fuel pump when oil pressure falls
in the oil gallery where the switch is located--the safety switch is activated when the oil pressure rises to about 6 pounds, and on shutdown--stops pumping
when the oil pressure drops below 6 pounds--------
 

Harold

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added pics--
 

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bammons

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So I think I will go ahead and use the original fuel pump based on what you guys are implying about the aftermarket units (and I already have a rebuild kit). As I have read your reply's I believe maybe it would be best for me to install a electric pump as well or rig up a emergency unit like George shows above. I did not realize that the peening I saw probably came from the factory and assumed someone else had done that for unknown reasons. So my question is now: Should I try to remove the peening on the two valves at the top to replace them (and maybe mess them up) or just leave the old ones in and simply put the new diaphram in.
 

Geo Hahn

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If they are secure and work I would leave them be. As I recall they should audibly move inside when you shake the pump -- they can also be visually inspected and possibly a 'suck & blow' test too. I have never had one fail though I have had one fall out.
 

charleyf

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I have successfully left them in place. It appears that the primary failure of a pump is the diaphram. I tried to remove the peened valves on one unit and felt like I ruined that unit. I will not try that again.
 
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