Author Topic: Quality, reliable mechanical fuel pumps  (Read 1703 times)

Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #15 on: July 08, 2025, 12:15:13 AM »
make sure to retain the oil switch in the fuel pump circuit. it is usually just above the oil filter on the TBI trucks, but you can use the oil gallery under the distributor as well. this serves 2 purposes, 1. if your relay dies, once you crank enough to get above 5 psi, the pump will energize from the oil switch alone 2. takes load off the relay contacts for longer contact life.

also don't use regular fuel line in the tank,.you need to get fuel hose rated submersible. usually black hose with a pink stripe on it.

  Tayto,
 I lobotomized the computer once I decided to go with the carburetor. I removed the check engine light and replaced it with a choke indicator light.
 Unfortunately I couldn't make the pump relay work in conjunction with the choke and light. The electric choke coil  would draw too much of the current that the relay would not energize.

 Not sure why it didn't work, but I gave up trying and just wired the relay through a switch under the dash instead.

 Would you know how to get the factory pump relay to work through the oil pressure switch and also energize the electric choke and the indicator light?
 The only way I can see to do both is to use 2 different oil switches. Any suggestions?

 Rick
 

Offline Kenth

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Re: Quality, reliable mechanical fuel pumps
« Reply #16 on: July 08, 2025, 12:58:32 AM »
Good luck finding a quality American product for cheap.
For cheap you get a Chinese product no matter what it says on the box.
And yes, the box may be made in the USA but the contents may not.

FWIW

Offline Kenth

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Offline taguy4

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Re: Quality, reliable mechanical fuel pumps
« Reply #18 on: July 08, 2025, 09:56:12 AM »
Why couldn't you just use a Carter M4891 style mechanical pump with a Jeep Wagoneer fuel filter, which has a built in return line port? I never liked the idea of putting an electric fuel pump in the gas tank for a number of reasons, and external electric pumps have problems of their own, such as being able to put them in the best location and wiring them properly so they are safe.

Offline quadrajam

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Re: Quality, reliable mechanical fuel pumps
« Reply #19 on: July 08, 2025, 01:35:32 PM »
Cadman, check out revolution electronics fuel pump controller 12003.
Available from the mfg. or several other online sites. Made in USA.
about 75$. Doesn't need oil pressure logic, works from tach signal.
I have one but have never got around to installing it yet. Gonna
have to put it on the DO list.

QJ

Offline quadrajam

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Re: Quality, reliable mechanical fuel pumps
« Reply #20 on: July 08, 2025, 04:59:07 PM »
What does a choke indicator light do....????
I used the original key-on wire for the v6 distributor to power up the v8 HEI distributor,
electric choke and at times a fast idle solenoid. plenty of voltage for all 3.
Fuel pump is another circuit that goes through the oil pressure switch. There is no automatic
prime. I have a button on the dash for that.
Should take very little current to power a relay and choke heater....

QJ

Offline tayto

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Re: Quality, reliable mechanical fuel pumps
« Reply #21 on: July 11, 2025, 07:29:43 AM »
I'm fairly sure GM had a 3 wire switch that would do the fuel pump and oil pressure light (choke light). I will have to search. In my square body I actually have the TBI running everything but the injection. sure is nice to change timing with a couple key strokes and then flash it to the ECM

EDIT: i think this is the correct sender:
https://www.rockauto.com/en/moreinfo.php?pk=44300&cc=1143964&pt=4588

my experience has been they all use the same plug but only use 2 pins instead of 1, so should be easy enough to add the extra wire.
« Last Edit: July 11, 2025, 07:35:44 AM by tayto »

Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #22 on: August 01, 2025, 07:44:07 PM »
  I figured out why I couldn't get the fuel pump relay to work with the electric choke through the oil pressure switch. I was trying to use the switch to ground the relay in the same way that the ECM did for the TBI system by controlling the relay ground. I need to use the oil switch to break the power from the relay to the pump instead.
 
  QJ, you mentioned that you put your regulator on your evaporator case, what was the reason for this location?
 Did you use the original fuel lines that ran up the transmission to the back of the engine, or did you reroute them?
 Did you use any hose? I've been looking at getting some stainless steel braided fuel hose to go between the regulator and the carburetor. I was thinking about cutting out the original braided hose for the TBI to use for this, but I don't know if this original hose will be in good enough condition.

 Also, the Edelbrock regulator that Summit Racing had recommended didn’t have a return port, so I sent it back and ordered an Aeromotive regulator. I'm much happier with this one, it's American made, but it is also adjustable from 3-60 PSI by changing the spring.

 I believe I will move the fuel lines from the inside of the frame rail to outside the frame to keep it cooler. I can bring it up from underneath the evaporator case and locate the regulator in front of it. What do you think?

 Rick

Offline quadrajam

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Re: Quality, reliable mechanical fuel pumps
« Reply #23 on: August 10, 2025, 06:36:10 PM »
The evaporator box was just a convenient place. no other reason.
See reply's 11 and 12 for routing info.

Offline Jeff K

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Re: Quality, reliable mechanical fuel pumps
« Reply #24 on: August 15, 2025, 03:56:20 AM »
 I never knew how well those mechanical fuel pumps worked until I fed the one the 462 that Cliff built. It was in a cherry 64 Bonneville with a four speed Hydro (3.97 first gear) and 2.56 rear end. By the way, that motor has well over 100,000 miles on it and is still going strong!

 It was a 1973 455, heavily ported 6x, 041 cam, topped off with a Brad Urban / Cliff Ruggles Quadrajet.

 It didn't run out of gas but used to kind of flatten out at 5000 rpm. Everybody was telling me to get an electric but I don't like them.

 So I bought a sumped, RCI, aluminum fuel cell and mounted it in the trunk.
 
 I kept the 1/4" return line and ran another 3/8", steel tubing fuel line to the pump. I put a tee on the fuel pump and ran both 3/8" steel fuel lines to it from the tanks sump.
 I was going to run one 1/2" steel line but the old mechainc down the alley from me told me to just use two 3/8" steel lines. He went on to say pulling fuel is different then pushing it and that two 3/8" lines work better than one 1/2" line!

Once I got it finished, It was like I installed a new engine! The first time I took it out, I thought something was wrong with the ignition because it was missing at high rpm. Turns out it was the Rev Limiter. My engine was cranking very quickly and hitting the 5200 rpm limit in what seemed like a split second that the Quadrajet was getting a good supply of fuel..

I changed the MSD pill to 5500 then to 6000.  That big boat would march right up to 140 mph with no trouble..

 I ended up with two 3/8" steel lines from the sump to a tee in the fuel pump. Then I connected the 1/4" return line to the supply line to the carb.




Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #25 on: August 28, 2025, 06:04:47 PM »
Cadman, check out revolution electronics fuel pump controller 12003.
Available from the mfg. or several other online sites. Made in USA.
about 75$. Doesn't need oil pressure logic, works from tach signal.
I have one but have never got around to installing it yet. Gonna
have to put it on the DO list.

QJ

 That looks like what I need. Thanks for the tip. Since I've eliminated the ECM my fuel pump relay doesn't have a priming function, I've got to use the override switch under the dash for that, which is kinda inconvenient, although it doubles as my in-line pump switch when I have the occasional supply problem.

 When going back to the in-tank pump this will come in handy. Much appreciated.

 Rick

PS: sorry for the delay in responding, I've got many projects going on and only get to work on my burb during slow times.

Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #26 on: August 28, 2025, 06:07:14 PM »
Good luck finding a quality American product for cheap.
For cheap you get a Chinese product no matter what it says on the box.
And yes, the box may be made in the USA but the contents may not.

FWIW

 So very true!

Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #27 on: August 28, 2025, 06:10:44 PM »
Why couldn't you just use a Carter M4891 style mechanical pump with a Jeep Wagoneer fuel filter, which has a built in return line port? I never liked the idea of putting an electric fuel pump in the gas tank for a number of reasons, and external electric pumps have problems of their own, such as being able to put them in the best location and wiring them properly so they are safe.

 My mechanical pump already has a return port, so there's no need for the Jeep/Chrysler filter, but I appreciate the tip. I have one of those filters already from when I was having issues with another vehicle with an electric pump. It beats trying to tee into the fuel line for a return.

Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #28 on: August 28, 2025, 06:19:28 PM »
What does a choke indicator light do....????
I used the original key-on wire for the v6 distributor to power up the v8 HEI distributor,
electric choke and at times a fast idle solenoid. plenty of voltage for all 3.
Fuel pump is another circuit that goes through the oil pressure switch. There is no automatic
prime. I have a button on the dash for that.
Should take very little current to power a relay and choke heater....

QJ

 QJ,
 I should have clarified that, the choke light is actually nothing more than a low oil pressure light. I started using the oil pressure switch to run the power through for the chokes on all my carbs on older vehicles that didn't have electric chokes from the factory. I copied the system in my '81 Malibu years ago and it's worked out great. That is until I tried to ground the fuel pump relay on this burb.
 Even if I could have made it work, I still wouldn't have had a priming circuit though.

Offline Cadman-iac

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Re: Quality, reliable mechanical fuel pumps
« Reply #29 on: August 28, 2025, 06:30:14 PM »
The evaporator box was just a convenient place. no other reason.
See reply's 11 and 12 for routing info.

 Yeah, I caught that after posting the question, sorry about that.
 I'm still looking for the ideal location for my regulator. I want it as close to the carburetor as possible, but not on the engine itself because of the heat exposure.
 However mounting it on the right inner fender or on the evaporator case means that I'd have to have a flexible line between it and the carburetor. Been considering cutting out the original braided fuel hose from the lines I removed in the conversion to use for this, but doing so eliminates the possibility of returning to the TBI if I ever wanted to, (which is a very slim possibility at best).
 Ideally, I'd like to find some new braided fuel hose, but I didn't want to have to buy an entire roll.