Wiring Path for Electric Fuel Pump

[Mark Maras]

Jalex, I'm curious about something. Who convinced you, or how did you convince yourself, that 3.2 p.s.i. isn't enough fuel pressure? We used to run an econo-rail dragster with a 327 c.i.    V-8 Chevy and a Holley carb. with 3 p.s.i. Roughly twice the cubic inches as a Z and the 327 was always run at full throttle. There was never a fuel starvation problem.

[Johnny wick]

Nobody convinced me. I just felt i could accomplish the following with 4.3 psi:

1. Dial both fuel mixture knobs of the 3 screws su carbs at 2.5 turns as initial setting without the engine shutting down. 

2. Accelerate without any popping or sputtering or stumbling in the carbs intake.

Really strange but this is how a feel when i am testing the car.

[Mark Maras]

 4.3 p.s.i. won't supply any more gas to the carbs than 3.2. The carbs only take as much fuel as the engine can use. The needle valve in the float chamber shuts off the fuel when the fuel reaches the preset float height and only dribbles a tiny amount into the float chamber to keep the fuel at the preset float height while you're driving. 

 Stumbling, popping and sputtering is NORMAL behavior in a cold engine with little to no choke, even in Panama. These symptoms could actually be a very good sign that your engine isn't running too rich. And if you're going to tell me that you didn't have to use the choke before, forget it. It ran like crap before.

Two questions for you.

 Does the engine run and drive reasonably well when it's cold with the choke on?

 How does the engine performance feel when the engine is warm and the choke is off.

[Patcon]

5 hours ago, jalexquijano said:

Nobody convinced me. I just felt i could accomplish the following with 4.3 psi:

1. Dial both fuel mixture knobs of the 3 screws su carbs at 2.5 turns as initial setting without the engine shutting down. 

2. Accelerate without any popping or sputtering or stumbling in the carbs intake.

Really strange but this is how a feel when i am testing the car.

Fuel pressure has nothing to do with this! The settings in the float bowls, tuning, carb balance do, not fuel pressure...

Mark beat me to it...

[Johnny wick]

Ill test it tonight. The engine does work fine with the choke on for 5 mins and once its warmed.

Edited February 27, 2018 by jalexquijano

[Mark Maras]

 OMG. Someone frame post #29. This is the best news I've heard. says Mark hesitantly. Could we be getting close? I think I'm going to start celebrating.

[Johnny wick]

11 minutes ago, Mark Maras said:

 OMG. Someone frame post #29. This is the best news I've heard. says Mark hesitantly. Could we be getting close? I think I'm going to start celebrating.

This is the same pump i have in my car. I was thinking of removing the small metal filter and adapting a fram G3 filter to protect it from the possible dirt on the fuel tank. What do you think?

[Mark Maras]

 Go for it. You could also attach the G3 to the existing fuel pump filter. You can't have too many filters.

[Johnny wick]

Took some pics of the pump for your reference. Would the position in any way affect the psi?

[Patcon]

20 hours ago, jalexquijano said:

Took some pics of the pump for your reference. Would the position in any way affect the psi?

 

Nope!

[Dan222000]

On 9/4/2014 at 8:46 PM, Carl Beck said:

This might help..

I have a 1973 Series II 240z that I am restoring.  I have both  relays A & B but was missing the V-3 modification harness.  I picked up a new harness from Ebay but can't figure out where two wires go.  Here's what I've figured out so far.

1. 6-pin harness goes to relay B

2. 4 pin harness goes to relay A

3. Black ground strap is grounded to relay B

4. long 2 pin harness goes to the fuel harness under the radio/console

5. there's two wires (yellow w/black stripe & Black with white stripe) - these are the wires I cannot figure out where they go.  Per the diagram on Harness B is looks like they go up above the glove box somewhere.

Can anyone help?

 

Thanks,

Daniel B.