This is a post to describe my electric fuel pump experience.

I am replacing the mechanical fuel pump due to vapor lock problems that I seem to experience at higher elevations. This problem has consistently showed up during trips to Big Bend National Park. After reviewing solutions to this problem, I have decided to try the electric fuel pump.

To determine how much flow was needed, I tried to come up with what I thought would be the worst case. And that is going highway speeds up a steep incline. This would be a worst case because this fuel consumption rate could last for a significant time. Therefore:

At 8 mpg:

70 mph = 8.75 gph

80 mph = 10 gph

85 mph = 10.625 gph

At 5 mpg:

70 mph = 14 gph

80 mph = 16 gph

85 mph = 17 gph

At 1 mpg:

70 mph = 70 gph

80 mph = 80 gph

85 mph = 85 gph

Therefore, depending on how fast you may be trying to accelerate, or how steep the hill is, the Jeep may need a large flow rate.

Test Point Locations Used Below:

A = The outlet port of the fuel filter that goes to the carb.

B = The discharge port of the pump, which is located just behind the transmission cross-member on the driver's side.

Pressure Regulator - Holley, P/N 12-804, 1-4 psi

Suction Filter - Deutsch, FF401

Test Point A:

Pressure (Port Blocked) = 1 psig (no matter how the pressure regulator was adjusted)

Flow Rate = 8 gph

Test Point B:

Pressure (Port Blocked) = 4.1 psig

Flow Rate = 21 gph

Driving Experience:

The Jeep would surge, as if running out of gas, during acceleration up a large incline.

Later, the Jeep would die while driving/coasting at slow speeds.

Pump was quite. Could not be heard in the cab.

Pressure Regulator - Holley, P/N 12-804, 1-4 psi

Suction Filter - Deutsch, FF401

Test Point A:

Pressure (Port Blocked) = 4 psig (started at 5.4 psig, easily adjusted to 4 psig)

Flow Rate = 77 gph

Test Point B:

Pressure (Port Blocked) = 14 psig

Flow Rate = 123 gph

Driving Experience:

Minor short distance driving as of 8-14-06. No problems so far.

Pump is noisy and can be heard in the cab when Jeep is at a stop light.

I will add to this post after I have driven the Jeep at highway speeds and up the same large incline that gave the first electric fuel pump problems.

I am replacing the mechanical fuel pump due to vapor lock problems that I seem to experience at higher elevations. This problem has consistently showed up during trips to Big Bend National Park. After reviewing solutions to this problem, I have decided to try the electric fuel pump.

__Determination of Flowrate Needed:__To determine how much flow was needed, I tried to come up with what I thought would be the worst case. And that is going highway speeds up a steep incline. This would be a worst case because this fuel consumption rate could last for a significant time. Therefore:

At 8 mpg:

70 mph = 8.75 gph

80 mph = 10 gph

85 mph = 10.625 gph

At 5 mpg:

70 mph = 14 gph

80 mph = 16 gph

85 mph = 17 gph

At 1 mpg:

70 mph = 70 gph

80 mph = 80 gph

85 mph = 85 gph

Therefore, depending on how fast you may be trying to accelerate, or how steep the hill is, the Jeep may need a large flow rate.

__Fuel Pump Testing__Test Point Locations Used Below:

A = The outlet port of the fuel filter that goes to the carb.

B = The discharge port of the pump, which is located just behind the transmission cross-member on the driver's side.

**Fuel Pump #1**- CarQuest, E8016S, Automotive Electric Fuel PumpPressure Regulator - Holley, P/N 12-804, 1-4 psi

Suction Filter - Deutsch, FF401

Test Point A:

Pressure (Port Blocked) = 1 psig (no matter how the pressure regulator was adjusted)

Flow Rate = 8 gph

Test Point B:

Pressure (Port Blocked) = 4.1 psig

Flow Rate = 21 gph

Driving Experience:

The Jeep would surge, as if running out of gas, during acceleration up a large incline.

Later, the Jeep would die while driving/coasting at slow speeds.

Pump was quite. Could not be heard in the cab.

**Fuel Pump #2**- Holley, P/N 12-802-1, Blue Electric Fuel Pump, 14 psiPressure Regulator - Holley, P/N 12-804, 1-4 psi

Suction Filter - Deutsch, FF401

Test Point A:

Pressure (Port Blocked) = 4 psig (started at 5.4 psig, easily adjusted to 4 psig)

Flow Rate = 77 gph

Test Point B:

Pressure (Port Blocked) = 14 psig

Flow Rate = 123 gph

Driving Experience:

Minor short distance driving as of 8-14-06. No problems so far.

Pump is noisy and can be heard in the cab when Jeep is at a stop light.

I will add to this post after I have driven the Jeep at highway speeds and up the same large incline that gave the first electric fuel pump problems.

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