Electric fuel pump

GT6Steve

GT6Steve

Well-known member
Joined
Jul 13, 2008
Messages
751
Location
Las Vegas Nevada
IS anyone running an electric fuel pump on the C3? I've lost another mechanical pump and am getting sick of their weaknesses (while ignoring the strengths).

My major gripe is cranking the engine excessively to get fuel to the carb for the start. An electric pump has it filled by the time the starter engages...

Pro's and Cons?

Steve
 
Wire it up with a normally closed time relay parallel to an oil pressure switch. This will provide priming and running 12v. The relay must be wired to ign. switched power. When turning ign on the timer in the relay will delay it opening. This delay gives you your fp. prime.
 
Logic Check

TT - As I understand the logic there, the system does this:

1. Key On - fuel pumps - Hold key to ign position, then
2. At relay Time-out, Starter fires
3. Release key
4. Drive, but,
... If Oil pressure drops - fuel pump Shuts Off. Clever (If I've got that right.)

Sounds effective and easy to wire with a Master Power On/Off and a push-button ignition switch.

I've got a Carter Electric I'm going to install to feed the low pressure regulator.


Cheers - Jim
 
phantomjock said:
TT - As I understand the logic there, the system does this:

1. Key On - fuel pumps - Hold key to ign position, then
2. At relay Time-out, Starter fires
3. Release key
4. Drive, but,
... If Oil pressure drops - fuel pump Shuts Off. Clever (If I've got that right.)

Sounds effective and easy to wire with a Master Power On/Off and a push-button ignition switch.

I've got a Carter Electric I'm going to install to feed the low pressure regulator.


Cheers - Jim
Click to expand...

Correct to what TT said, but a far cheeper is a push button on the dash to effectively jumper the oil pressure switch, that enables you to just tap the button for a time to fill the carb up, then hit the gas to start.....I have found that a Carter pump, best in the business IMO, will put out too much pressure and push the float valve off seat in a Q jet.....many years ago I put a resistor is series with the pump to cut the power down, curing the problem.....I forget the value of the resistor, but it was very LO....like 5 ohms or so.....:clap:
 
key off relay is closed (since it's normally closed) but no power to pump because it's from an ign. switched source. Key on, 12V ign. sw. power to relay...pump ruins. relay timer triggers and after X secs the relay goes to the off pos. Pump stops so you can actually leave the ing. on without the pump running all the time. This interval gives you pump prime. Start the car, oil pressure comes up and the pressure switch supplies voltage to the pump

End up not starting the car? No problemo. Turn the ign off and whenever you turn it on again the relay simply does the same thing again. Even IF the relay craps out you will still be able to start the car as the OP switch needs very little pressure to close the contact. Something in the order of 5 psi or so.

Gene, why hack up your dash with some sort of unsightly button if you can wire it in using a simple relay and a stock GM OP switch that came on many many efi cars and have it so that it uses cheap factory parts for servicability, looks stock and lets you have a non hacked up ride with holes in the dash. Your mentality is the reason why all cars I ever got out of the US had holes drilled here and there for knobs and other misc. shit.

As for the restrictor. When you step up to an electric pump you might as well run a return style regulated system for continuous cool fuel supply.
 
Steve, I'm really surprised you're having problems with the mechanical pump. The pump on my 81 has been on there at least 10 years with no problems. But I am planning on an electric pump just to get that obnoxious mechanical pump out from under the hood. I like the way Marck described it but I'm really not sure that a car driven very frequently would even need that relay. Unless the car sits for weeks on end, the fuel bowl should keep enough fuel in it to run the engine until you have oil pressure and the pump has refilled the bowl.
At least that was the case on my 240z. I had a fuel pump wired in off a relay getting power from the ignition only. I did not have it through an OP switch (although I do agree that is a very nice safety feature to have). The point is, the pump ran only and whenever the key was in the "run" position. The only time I ever had to do any abnormal amount of cranking to get fuel into the carburetor is if I had removed the carburetor for some reason, or had let the car set for a month+. Even then, it was only a matter of a few additional seconds of cranking before the bowl was filled enough for the idle and primary circuits to pull gas.
 
I have an Aeromotive Street and Strip electric pump on my 70. Down steam of the pump is a large Aeromotive canister fuel filter. The fuel filter allows me to get rid of those porous bronze cylindrical blocks in the Holley fuel inlet ports. A Holley pressure regulator is adjacent to the Holley. The Street and Strip pump is powered via an Aeromotive speed controller. It senses engine speed via the distributor ..it works with either old fashioned breaker points or a HEI tachometer electrical output signal. The speed controller runs the pump at a relatively law speed at idle with a reduced (chopped 12 vDC) voltage until engine rpm get to ~2500 rpm, when it applies full power to the pump. When the speed controller senses no engine rpm, i.e. the engine if off, it applies electrical power to the pump for about 10 seconds, and then turns the pump off....so you don't need an oil pressure switch to turn the pump off. The speed controller makes a lot of sense, since you don't need the pump running at full speed when the engine is at idle, or off idle at a cruise speed.
 
Twin_Turbo said:
key off relay is closed (since it's normally closed) but no power to pump because it's from an ign. switched source. Key on, 12V ign. sw. power to relay...pump ruins. relay timer triggers and after X secs the relay goes to the off pos. Pump stops so you can actually leave the ing. on without the pump running all the time. This interval gives you pump prime. Start the car, oil pressure comes up and the pressure switch supplies voltage to the pump

End up not starting the car? No problemo. Turn the ign off and whenever you turn it on again the relay simply does the same thing again. Even IF the relay craps out you will still be able to start the car as the OP switch needs very little pressure to close the contact. Something in the order of 5 psi or so.

Gene, why hack up your dash with some sort of unsightly button if you can wire it in using a simple relay and a stock GM OP switch that came on many many efi cars and have it so that it uses cheap factory parts for servicability, looks stock and lets you have a non hacked up ride with holes in the dash. Your mentality is the reason why all cars I ever got out of the US had holes drilled here and there for knobs and other misc. shit.

As for the restrictor. When you step up to an electric pump you might as well run a return style regulated system for continuous cool fuel supply.
Click to expand...

:shocking: I did that button in the previously drilled to hell dash in my 40 y/o motor home, never added a hole, in fact there are many vacant holes....not that I care......my vette has a totally custom console panel in place of the old HVAC/ashtray nice and neat....really do need to clean up the control panel though, it's only been in place about 18 years now, getting almost tired as me......:hissyfit::shocking::beer:
 
mrvette said:
:shocking: I did that button in the previously drilled to hell dash in my 40 y/o motor home, never added a hole, in fact there are many vacant holes....not that I care......my vette has a totally custom console panel in place of the old HVAC/ashtray nice and neat....really do need to clean up the control panel though, it's only been in place about 18 years now, getting almost tired as me......:hissyfit::shocking::beer:
Click to expand...

The switches to control my fuel pump(s) are in the compartment where the jack was located. Actually, my fuel pump situation is more complicated than originally posted. I have redundant fuel pumps. The Aeromotive Street and Strip is the primary pump. The redundant pump is a heritage holly electric pump. If my Aeromotive pump/speed controller fails, I have the option of switching over to the heritage Holley. I have fuel flow check valves that prevents leakage of the operative pump flowing back through the powered off pump. I did all the plumbing myself with Copper/Nickel/Steel alloy fuel lines. (CuNiFer). I probably used about 6 to 8 feet of alloy fuel lines in the car...However i probably bought close to 30 feet of fuel lines to make the system...Everytime I made a fuel line with all the bends and it didn't fit, I threw it away and started all over again. I think there was one line segment, I made 6 times before I made it correct. I can get to be very obsessive about doing everything correct. My attitude is that if someone else can make something with hand tools, I can make it also. It's just that me being a beginner, I have to accept making mistake after mistake until I get it correct.
..................
PS I like the CuNiFer alloy lines. There is a US distributor. Some European car companies have used this alloy (Volvo). It's a little bit softer than steel lines so double flares are easy to make with simple hand tools. It's no way as soft as copper. It's copper nickel alloy component means it is corrosion resistant. OK, when you use it, it does get that patina associated with copper...doesn't have the bling of stainless steel.

The money I spent on the Aeromotive pump/speed controller/filter, Holley fuel pump/regulator parts, the CuNiFer lines, and the AN fittings and tools (individual tube benders, double flaring tools, AN aluminum wrenches) probably was edging up against a total of $1000.

My concern now is that with my new Quanta OEM duplicate fuel tank and new Holley carb, etc, the 10% ethanol in the gasoline here is going to cause some very destructive corrosion. Here in California, where I live you can't buy alcohol free gasoline. I've plans to buy racing gasoline ($$$$) that's alcohol free. Don't drive the 68 much so maybe it's' a cost effective idea. If you want to buy racing fuel, do not buy "oxygenated fuel." Oxygenated is a code word for alcohol. Also, for an older car, be careful about buying leaded racing gasoline...there's a big fine for using leaded fuel today.
 
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That's what I use for brake lines, Cunifer. It's far superior to copper... and it's great to work with.
 
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