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Electric fuel pump question

NutmegCT said:
Tinster: <span style="font-style: italic">PS: No fuel additives were used- straight gasoline.</span>

I think Dale means he didn't pour any bottles of additive into his fuel.

T.

<span style="color: #990000">Exactly Tom!
Everything is new, tank cleaned spic and span with
10 gallons of pre-filtered, high test gasoline right
from the pump at a new station with new underground
tanks. I added no bottles of anything.

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Takin' a coffee break:

I am half way completed connecting the electric fuel
pump to the carbs and fuel tank. The pump runs like a champ.

I'll report back later.

PS:

Pump No1- Pedro's Spitfire pump- filled w/ sand; stopped pumping
Pump No2- 3rd world pump- defective,quit pumping- no idead why- I trashed it
Pump No3- Used OEM gift from BCF member- quit pumping- old age I reckon.
Pump No4- 3rd world pump- defective, about 16 psi, flooded my engine compartment
Pump No5. 3rd world pump- functional when removed to replace entire fuel delivery system last month.
Pump No6- OEM Rego rebuild- unknown; still in diagnostic phase.

d</span>
 
Dale - before you crank 'er up again, have you removed that soft (foam?) insulation you added under the carbs? Some of us thought it was an accident waiting to happen, as it seemed very likely to absorb any gas that dropped down on it.

Edit: insulation/ heat shield material

Tom
 
NutmegCT said:
Dale - before you crank 'er up again, have you removed that soft (foam?) insulation you added under the carbs? Some of us thought it was an accident waiting to happen, as it seemed very likely to absorb any gas that dropped down on it.

Tom

Thanks Tom,

Not foam- some insulation material
that does not burn. But yeah, it could
fuel and ignite. But without it, I seem
to get vapor lock from hot carb bowls.

d
 
kodanja said:
Why do people pefer to go to an electric fuel pump over a mechanical one?

I've never had any problems with my mechanical ones over the years.

The clincher for me was when my car sat for a couple of months and it was hard to start like it had jumped out of time. I discovered there was 4 1/2 gallons of oil and gas mix in the crank case. Apparently gas had seeped past the seal on the mechanical pump and into the crankcase. This is very common.
 
Especially maddening now with ethanol as a mandated additive! Some of those pumps are running original diaphragms, some "kits" are older and still susceptible to ethanol meltdown. Either way, the crankcase gets fuel-filled.
Some results from this condition can be dramatic. :eeek:

Electric pump also supplies fuel to carbs after the car has sat a while, no "extra cranking" to fill bowls. Kill switches can be installed on 'em, THAT'S hard to do with a mechanical pump.
 
on a side note. I bought a carter electric pump, the only problem is it ran all the time with the key in the on position, so I bought a brass "T" fitting and screwed it in at the oil pressure switch outlet on the block, then purchased another oil pressure switch at napa Echlin # OP6092, Closes at 5 psi. ran the hot wire thru the new switch so the pump comes on only when I have oil pressure greater than 5 psi. I have never had a problem starting the car since the pump will not kick on till the engine starts and the oil pressure comes up

Hondo
 
Tinster said:
How does the electric fuel pump compensate for
different demands from different engine rpms?

Electric fuel pumps like you've purchased work the same as a mechanical one. The difference is instead of a camshaft lobe pulsing the diaphram, it's done electronically via a solenoid. There are a set of "make or break" contacts connected to the diaphram.

When the system is empty or low in pressure, the contacts touch and the solenoid kicks. The spring pushes the diaphram back. This repeats until fuel like pressure pushes back against the spring, keeping the contacts from touching. This is why the pump clicks rapidly when you first turn the ignition key on, and then stops.

Cheap ones burn their contacts. Just be aware of that.

A decent example of how a mechanical fuel pump works can be seen here: https://www.secondchancegarage.com/public/535.cfm An electronic pump works the same way.
 
hondo402000 said:
the only problem is it ran all the time with the key in the on position,
Good point, Hondo, though most people just live with that. Was also the original arrangement on my Stags ... I managed to hydrolock the motor once by leaving the key on while working on something ! One of the float valves leaked a bit, and the fuel ran into the manifold ...

Come to think of it, that may have had something to do with the blown headgasket a few weeks later. The starter coming up against that slug of fuel might have disturbed the head/gasket just enough ... that's when it started running hotter than before though the leak had to get worse before I was sure it was there.
 
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