Fuel pump help
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5th Wheeling
Joined: Feb 2023
Posts: 46
Likes: 3
From: Fort Hood
Fuel pump help
Got a 1984 f250 here with the 460 in it and it has an in-line fuel pump installed on it. I’m running an aftermarket 1406 that the PO put on it back before 05. With my research I’ve only seen that it should have a mechanical fuel pump not this electric one. If this is not something from the factory could someone help me with where the mechanical would be on the motor. And if you guys know more than me, how big of a difference is running a 2.5-4 psi pump instead of what edelbrock calls for of around 5.5.
Side note I also lose all fuel pressure after the motor starts but she still runs.
Side note I also lose all fuel pressure after the motor starts but she still runs.
FTE Legend
Joined: Nov 2015
Posts: 30,935
Likes: 4,124
From: Angier, NC
I am not up on the later larger trucks with the big motor but I think yours would be either a motor driven pump like you have searched or in tank electric pump.
AlsoI want to say some of the big motor trucks had a Hot Fuel Bypass (HFB) that would return some fuel back to the tank.
This was so the fuel in the fuel line did not get too hot and boil causing a vapor lock.
Have you followed the fuel line from the tank to the carb?
Can you see the tank sending unit and if so how many wires are going to it and hoses?
2 wires would be no in tank electric pump.
Not sure where the HFB return goes but would think the sending unit, so 2 hoses, 1 large (supply) and 1 smaller (return) one.
If motor driven fuel pump I believe Ford had them all on the left side to the front like below the PS pump.
Left & right is always in the driver seat.
Fuel line would run from the sender, short rubber hose to a metal line that runs along the frame up to the motor where there was another short hose to the pump. Then metal line from pump to carb.
Now I think the HFB valve is in that metal line to the carb and it bleeds off fuel back to the tank.
You did not say if you had more then 1 tank?
Dave ----
AlsoI want to say some of the big motor trucks had a Hot Fuel Bypass (HFB) that would return some fuel back to the tank.
This was so the fuel in the fuel line did not get too hot and boil causing a vapor lock.
Have you followed the fuel line from the tank to the carb?
Can you see the tank sending unit and if so how many wires are going to it and hoses?
2 wires would be no in tank electric pump.
Not sure where the HFB return goes but would think the sending unit, so 2 hoses, 1 large (supply) and 1 smaller (return) one.
If motor driven fuel pump I believe Ford had them all on the left side to the front like below the PS pump.
Left & right is always in the driver seat.
Fuel line would run from the sender, short rubber hose to a metal line that runs along the frame up to the motor where there was another short hose to the pump. Then metal line from pump to carb.
Now I think the HFB valve is in that metal line to the carb and it bleeds off fuel back to the tank.
You did not say if you had more then 1 tank?
Dave ----
Thread Starter
|
5th Wheeling
Joined: Feb 2023
Posts: 46
Likes: 3
From: Fort Hood
I am not up on the later larger trucks with the big motor but I think yours would be either a motor driven pump like you have searched or in tank electric pump.
AlsoI want to say some of the big motor trucks had a Hot Fuel Bypass (HFB) that would return some fuel back to the tank.
This was so the fuel in the fuel line did not get too hot and boil causing a vapor lock.
Have you followed the fuel line from the tank to the carb?
Can you see the tank sending unit and if so how many wires are going to it and hoses?
2 wires would be no in tank electric pump.
If motor driven fuel pump I believe Ford had them all on the left side to the front like below the PS pump.
Left & right is always in the driver’s side
Dave ----
AlsoI want to say some of the big motor trucks had a Hot Fuel Bypass (HFB) that would return some fuel back to the tank.
This was so the fuel in the fuel line did not get too hot and boil causing a vapor lock.
Have you followed the fuel line from the tank to the carb?
Can you see the tank sending unit and if so how many wires are going to it and hoses?
2 wires would be no in tank electric pump.
If motor driven fuel pump I believe Ford had them all on the left side to the front like below the PS pump.
Left & right is always in the driver’s side
Dave ----
upon cleaning and looking there is a mechanical pump right on top of the oil filter!
Moderator
Joined: Jan 2001
Posts: 56,995
Likes: 2,741
From: Virginia
From the experience I just had with my little Bronco, I would keep the frame mounted electric pump. Just make sure you bypass the original mechanical pump.
With the new fuel they sell, it vapor locks terribly. I have been having problems with vapor lock on my 84 Bronco II, but the other day I filled up and it must have been winter blend fuel and it was a hot day. It got hot this time and it quit on me completely. I had already ordered a electric pump, I just hadn't put it on yet. So I had to install it now, about midway down the frame. It runs so much better, even on that same tank of fuel. No vapor lock problems now. I would keep your electric fuel pump, if it's not working correctly get another one. There is a reason the factory went to electric pumps, especially on the 460's back then.
With the new fuel they sell, it vapor locks terribly. I have been having problems with vapor lock on my 84 Bronco II, but the other day I filled up and it must have been winter blend fuel and it was a hot day. It got hot this time and it quit on me completely. I had already ordered a electric pump, I just hadn't put it on yet. So I had to install it now, about midway down the frame. It runs so much better, even on that same tank of fuel. No vapor lock problems now. I would keep your electric fuel pump, if it's not working correctly get another one. There is a reason the factory went to electric pumps, especially on the 460's back then.
FTE Legend
Joined: Nov 2015
Posts: 30,935
Likes: 4,124
From: Angier, NC
Dave I dont have a issue using an electric pump but he said his is mounted to the inner fender well in the engine bay!
As we all know electric fuel pumps do not pull fuel vary good and why they should be mounted as close to the tank as can be and should be below fuel lever so it stays wet.
3651w 95 guy what dose your switching valve look like?
Is it a 3 port valve with 1 wire going to it or something different?
What ever you have you (I would) move that pump or a new electric pump to just after (starting from the tanks) the tank switching valve so it is a little closer to the tanks and hope it stays more wet than up where it is at now.
Just my .02
Dave ----
As we all know electric fuel pumps do not pull fuel vary good and why they should be mounted as close to the tank as can be and should be below fuel lever so it stays wet.
3651w 95 guy what dose your switching valve look like?
Is it a 3 port valve with 1 wire going to it or something different?
What ever you have you (I would) move that pump or a new electric pump to just after (starting from the tanks) the tank switching valve so it is a little closer to the tanks and hope it stays more wet than up where it is at now.
Just my .02
Dave ----
Thread Starter
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5th Wheeling
Joined: Feb 2023
Posts: 46
Likes: 3
From: Fort Hood
From the experience I just had with my little Bronco, I would keep the frame mounted electric pump. Just make sure you bypass the original mechanical pump.
With the new fuel they sell, it vapor locks terribly. I have been having problems with vapor lock on my 84 Bronco II, but the other day I filled up and it must have been winter blend fuel and it was a hot day. It got hot this time and it quit on me completely. I had already ordered a electric pump, I just hadn't put it on yet. So I had to install it now, about midway down the frame. It runs so much better, even on that same tank of fuel. No vapor lock problems now. I would keep your electric fuel pump, if it's not working correctly get another one. There is a reason the factory went to electric pumps, especially on the 460's back then.
With the new fuel they sell, it vapor locks terribly. I have been having problems with vapor lock on my 84 Bronco II, but the other day I filled up and it must have been winter blend fuel and it was a hot day. It got hot this time and it quit on me completely. I had already ordered a electric pump, I just hadn't put it on yet. So I had to install it now, about midway down the frame. It runs so much better, even on that same tank of fuel. No vapor lock problems now. I would keep your electric fuel pump, if it's not working correctly get another one. There is a reason the factory went to electric pumps, especially on the 460's back then.
Thread Starter
|
5th Wheeling
Joined: Feb 2023
Posts: 46
Likes: 3
From: Fort Hood
Dave I dont have a issue using an electric pump but he said his is mounted to the inner fender well in the engine bay!
As we all know electric fuel pumps do not pull fuel vary good and why they should be mounted as close to the tank as can be and should be below fuel lever so it stays wet.
3651w 95 guy what dose your switching valve look like?
Is it a 3 port valve with 1 wire going to it or something different?
What ever you have you (I would) move that pump or a new electric pump to just after (starting from the tanks) the tank switching valve so it is a little closer to the tanks and hope it stays more wet than up where it is at now.
Just my .02
Dave ----
As we all know electric fuel pumps do not pull fuel vary good and why they should be mounted as close to the tank as can be and should be below fuel lever so it stays wet.
3651w 95 guy what dose your switching valve look like?
Is it a 3 port valve with 1 wire going to it or something different?
What ever you have you (I would) move that pump or a new electric pump to just after (starting from the tanks) the tank switching valve so it is a little closer to the tanks and hope it stays more wet than up where it is at now.
Just my .02
Dave ----
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5th Wheeling
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