Pull through priming electric fuel pump for old cars: Help while cranking Airtex E8251 Carter P74021

This outlines the process of adding an electric fuel pump inline to aid in cranking. This is using an electric fuel pump on carbureted engine. While not in use, the mechanic fuel pump pulls fuel through it. This was completed on my 1964 Buick Wildcat with AC. Fuel pumps requires a fuel filter inline to retain the warranty, so I initially went with a Wix 33063, but after finding it was a 12 micron filter, not good for pulling applications, I changed to a 74 micron K&N 81-0303, shown in the affiliate links below. The K&N filter is a rebranded Facet 479735.
In 2019, Trico brands, already the owner of the Carter fuel management trademarks, acquired the Airtex brand. Multiple websites report the Carter inline electric fuel pump P74021 as a direct replacement for the Airtex E8251. I have listed it for convenience but have not tested it. Combing over all the specifications, they look identical, except the Airtex was rated 2.5-4.5 PSI, whereas the Carter is 3.5 to 5.5 PSI. A Summit article shows that this pressure will still fall within the maximum prescribed by many carburetor manufacturers.
Affiliate Links:
Fuel Pump: amzn.to/3Q8Y48C
Inline Filter amzn.to/3xfFM9b
Thread sealant: amzn.to/2xDu9Q3
Hand vacuum pump: amzn.to/2Ns23iN
Mounting bracket: amzn.to/2UrvaUn
Butt electrical connectors: amzn.to/2WRR5FW
Ring terminals for ground: amzn.to/2wAJWiJ
Steel fuel line "quick disconnects": amzn.to/3aNpOJ1
Music: Seasons by roljui

[@termonostruman]

well explained, but if you rn your car everyweeks you dont need that

[@InternetDude]

This would have been better without the music but good video otherwise.

[@loathecliff9364]

Much appreciated. Straight to the point, unlike so many others. (PS wish you didn't add Muzak)

[@BB-gi1uv]

If the stock fuel pump is working properly then the amount you cranked the engine would more than fill the carb. The problem in most cases is the automatic choke isn’t working properly. I have seen where people crank and crank forever but if the fuel going to the engine isn’t rich enough (choke on) you can be there cranking until the battery goes dead.

[@69butternut.]

Exactly! Sometimes people don’t understand the correct starting procedure either. I never saw if he touched the gas before that first crank either. On my 69 Impala with quadrajet, for example, you have to put foot to floor once. It closes the choke plate and helps to draw a fuel shot into the carb. That will get it started. Without doing that you can crank and crank like this demonstration. That’s leaving my car for weeks too and not 6 days. If it’s cold out then it may not keep running with one pump. The manufacturer covered that too and said to give it 3 pumps in winter.

[@EBeas-y6k]

That may be true in some cases, but this is also a common symptom from leaky well plugs. This is a decent solution if you don’t want to mess w the carb.

[@termonostruman]

well try the choke so, before the electric pump

[@DAT240Z72]

Just install a one way valve? Keeps the fuel from draining back. Provides just enough fuel to turn the engine over.

[@1964buick]

Unfortunately, it is an evaporation problem, not a drain back issue.

[@Ryz240]

Curious why you need the steel fuel line quick disconnect? Wouldn't the fuel pump still allow fuel to travel through when it's turned off and or broken? Deciding if I want to put in a Y line next to the fuel pump with a check valve.

[@1964buick]

More of a phyiscal failure than anything. If the pump died electrically, agree 100%, fuel would still flow. If the can cracks on the fuel pump, or the input filter plugs after hours, the steel quick disconnect would instantly correct.

[@Ryz240]

@@1964buick got it that totally makes sense thanks! How has the pump held up? wondering if i should buy the holley or K&N carb pump though they are a bit more. Cheers!

[@1964buick]

@@Ryz240 It has held up just great in the 3+ years I have had it. If you switch to a different pump than listed, I believe you are looking for a solenoid style pump to allow fuel to flow through it.

[@Ryz240]

@@1964buick sounds great I’ll go with this pump then! Thanks for the info!

[@awdjon]

Very good video. Thank you! This is my next mini project on my 70 Eldo

[@garymccord4277]

This seems to work very well. I going to do to my 1957 belair 4 door sedan always have to prime the carburator before starting . This fix looks like it will work great .Thanks and I give you an A++++++

[@coachgeo]

welllll shiatttttttt why could I not find this video months ago..... was going NUTS trying to find pull thru pumps for this reason. Did discover Faucet Purlator has a whole line of them too. Not sure how competitive priced they are. Added complication though is I needed diesel compatibility.

[@termonostruman]

youcan run them on paralell so use your old mechanic pump,, and use the lectric just for start

[@coachgeo]

@@termonostruman yep... more plumbing... more places to leak. which on a diesel just adds a whole new level of PITA compared to a Petrol car. Chasing air leaks suck

[@Santosty1]

Great video! I was looking for a video just like this. Doing this exact set up on my Riviera.

[@jasonthomas9364]

Good video, straight to the point

[@honda90084]

Nice Job. This is exactly what I need. But I'm going to find one with enough psi that it will run down the hay on just incase the mechical pump goes out I can use it as a back up to get home if needed. Main reason is for priming the fuel system an then shut off tho. Do you know if all inline electric pumps pull through if shut off?

[@1964buick]

Not all fuel pumps will pass fuel without power, which is why I went with the Airtex in the video. My understanding is the pump has to be a solenoid style, not an impeller type to allow the mechanical pump to still draw.

[@Bamakettles]

An antenna bracket...of course!

[@hugegizmo151]

Do these style of pumps run constantly

[@1964buick]

They are rated to run constantly, however in my application it is only for priming.

[@davidreali9642]

Where the the switch on amzon u used noticed wasnt linked

[@1964buick]

I'm using a Buick switch, specific to the car, but any normally open, momentary button or switch would work. Here is an example: amzn.to/3deZ3kS

[@TheBack-Yardian101]

Does the power to the pump need to be left on or is it just for priming

[@1964buick]

In my application, it is just for priming. The pump could be used full time; however you would want to add a safety device such as an oil pressure switch to turn off the pump when the engine stops running.

[@TheBack-Yardian101]

I wired it to the ignition. Thanks for your response

[@tepp4083]

could i run the electric pump, inline with my mechanical pump, at all times? not just for priming. and if so, would I get my power from the sending unit wire? i have a 1962 Impala

[@1964buick]

You could run an electric fuel pump at all times with the mechanical inline, just make sure it is low enough pressure to not overwhelm your fuel system. Also, you'll need to decide a safety circuit so the pump is not running when you don't need it to, or in the event of an accident. Many use an oil pressure safety switch.

[@stuckinmygarage6220]

Nice presentation and thank you. Don't forget the safety pressure switch off the oil circuit. Standard equipment on later cars. SMP PS-64 is a good example. Best regards!

[@1964buick]

That's a great point. For my installation, the switch is momentary, so I don't have a need for a pressure switch. Standard Motor Parts switch you recommend is linked here: amzn.to/3yP92oY

[@jimgee2676]

do ya have any vapor lock issues on a hot day , if yes what ya do to fix it

[@1964buick]

I haven't had any.

[@itsruffoutchea6636]

@@1964buick my question is does priming through mechanical fuel pump hurt the diaphragm or check valves in it? I ask this question because after using a booster pump before on Skylark I started having leak on a new mechanical fuel? Booster pump was only a 4lb psi.

[@InternetDude]

You need to get a fuel filter from an AMC Eagle that has a return line on it. Then run a return line back to the tank. Make sure the vent line on the filter is toward the carb and at the "top".

[@spymaine89]

WAY TOO COMPLICATED . PUT IN AN INLINE CHECK FUEL CHECK VALVE

[@steven-ky2ps]

A check valve won't help when it's the modern gas evaporating from the bowl of the carburetor that's the problem.

[@gerardomendoza9688]

That's just pure lazyness for not opening the hood and pouring some fuel in the carb. you better of putting gas in the carb than to go through all that un-original installation crap...