Question of the Day

[bravekozak]

E9BZ-8501-AX

[william]

Forgot. To mention i have the capri b6d.
I went to autozone and grabbed their duralast unit. For $38.00
Has a life time warranty. And feals tighter than the Bosch did when new.
So ill try to make it to work tomorrow so i can change it in a heated shop.
Its 30°f out and i hate cold fingers lol.

[bravekozak]

My question of the day is how do you remove the red and black terminals from the electric fuel pump lid. Are they pressed in? screwed in? Anyone know?

[william]

Will miata plug wires work with the capri b6d-t
i can't seem to find quality wires for the capri last
wires i got melted in the head. And i have to swap back to my ac delcos .
And they are now missing under load.

[shadetree]

Get ngk for a escort gt bp ! Like 43 bucks shipped ! And yes they have red as well ! Lol

[bravekozak]

I have a great question for everybody today.
I have a carb that requires very low pressure. But I have an electric fuel pump.
I read this online:
Voltage has a direct effect on pump output. Apply more voltage and the pump will spin faster, pumping more fuel. Apply less voltage and the pump will slow down, pumping less fuel.

Can I just put a resistor in line, somewhere where it won't cause a fire if it gets hot? Will running the pump at 9 volts all the time damage the motor? or make it last longer? It would certainly be quieter.

[db2u]

If you slow down an EFI pump, it will drop the flow rate, but I dont think it will drop the max pressure. If I am correct I think that carb needs like 3-5psi and efi is around 30. I dont think you can use a fuel pump intended for EFI on a carb.

[bravekozak]

I spun an extra pump I have with a 9V battery. It runs a lot slower (like half speed). Why won't the pressure drop? Doesn't less flow mean less pressure? I have a bypass regulator up front. But the little carbies don't need even what the regulator lets through.

Does anyone know what the resistance is on the fuel pump motor? Does 1.4 ohms sound right? Do I need a 3.4 ohm resistor to get from 12V to 9V?

[db2u]

I don't know how to explain my logic, lets just say I would be very surprised if you can get this to work. high volume low pressure pump vs low volume high pressure pump. If you reduce the speed of the high pressure pump you are also reducing the volume I believe. Regardless, even if my logic is wrong, I think you are going to have to do more than a 25% reduction in voltage to get down to the right pressure for a carb.

Also, your regulator is exactly that... it sets a maximum PSI. Your output from the regulator wont change until your input pressure goes below the set point of regulation. At that point it is no longer doing anything at all and the pressure going to your carb would be fluctuating.

[bravekozak]

All I want is quieter + less return flow to the tank. I will buy a carb range fuel pressure gauge and test. I just need to calculate how many watts for the resistor. 10W?

[jason_]

If the gears have near zero clearance, it can spin like a turtle and still make pressure.

Compare a 1/2" outlet hydraulic pump to a 2" outlet trash pump, regardless of rpm or volume.

The trash you can block off and pump will cavitate. Block the hydraulic pump and you'll bust the housing (relief valves anyone?)

And you'll need a fat high wattage resistor to hold up if that pump pulls any apps under load, and turning electric motors slower is a no no., especially if it uses speed to cool itself with winding fins. Electric fuel pumps use the fuel to cool themselves.

Have fun.

Sent from my rooted HTC Supersonic using Tapatalk 2 Pro

[bravekozak]

I measured a 10.4 amp draw at 12V.
I will test the draw at 9V and report back.
There is lots of room in my rear wheel well for a resistor to cool off. I don't have any vapor controls.
I assume low pressure fuel pumps have fewer teeth in the gears. I checked for a Denso low pressure pump but couldn't find one.
I will be operating on a dead pump to see what's inside. I will post pics during the surgery.

[bravekozak]

Interesting. The draw with a 9V battery on the electric fuel pump is almost the same. Just a tick less.

[bravekozak]

Does that mean the resistor should be capable of dissipating 30W?
Or is my calculation wrong?

I guess I could just mount a metal case resistor right to the body sheet metal to get rid of the heat.

[jason_]

I'm not doing your homework, no offense.

Sent from my rooted HTC Supersonic using Tapatalk 2 Pro