General Category > Quadrajet Carb Talk and Tips
Quality, reliable mechanical fuel pumps
quadrajam:
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
tayto:
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.
Cadman-iac:
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
quadrajam:
The evaporator box was just a convenient place. no other reason.
See reply's 11 and 12 for routing info.
Jeff K:
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.
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