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I really don't know how to put this in a good order, but here goes. On my 87 F-150 that I'm currently putting a 4bt in; there are 3 fuel pumps a lift pump in each tank and an extra in the frame rail by the engine bay... Reading other threads it is my understanding people are using different pumps but is there any way to use the factory fuel system? Maybe just the lift pumps? Or all of them and a fuel pressure regulator with a return line? I'm just a bit confused and nobody around here knows what is right, so a little insight would be greatly appreciated :)
 

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I'm putting my 4BT in a 90 F-150. It has an in-tank pump in each tank but no booster pump on the frame. If you do decide to use the stock pump set up you'll definitely need a regulator and a fuel return line to regulate the supply to the VE pump to no greater than 20-25 psi I believe. I hate in-tank pumps, I want something I can repair in a few minutes rather than having to drop a tank so I am going with the Cummins lift pump, I don't see how it can get any better than that as long as you don't need a huge fuel flow. Throw a spare lift pump in the glovebox and it could be changed in a few minutes on the road vs. screwing around with an in-tank system. Just my humble opinion. What I am going to do is to use the rear in-tank pump to transfer fuel from the rear tank to the front tank and draw off the front tank with the Cummins lift pump. That way I don't need the complexity of a switching valve, just a toggle switch to turn on the rear pump and a red light to remind me its on.
 

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Discussion Starter #3
Will just the lift pumps generate too much psi?
 

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The stock '89-'90 Cummins 6BT diaphragm lift pump is plenty of pump for the 4BT. You gotta figure if it's enough to feed a strong 6BT it must be enough to feed a 4BT.

VE Injection pumps can't take high pressure pumps without a regulator. 5lbs to 7lbs feed it okay, with a max of 10-13 as I recall. High pressures blow the seals. The 4BT with VE pump doesn't actually need the lift pump at all at stock fuel ratings, but it takes a lot of stress off the VE with one, so Cummins installed. Replacement 6BT diaphragm pumps go for about $60 if you shop around, and they are readily available.
 

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The stock '89-'90 Cummins 6BT diaphragm lift pump is plenty of pump for the 4BT. You gotta figure if it's enough to feed a strong 6BT it must be enough to feed a 4BT.

VE Injection pumps can't take high pressure pumps without a regulator. 5lbs to 7lbs feed it okay, with a max of 10-13 as I recall. High pressures blow the seals. The 4BT with VE pump doesn't actually need the lift pump at all at stock fuel ratings, but it takes a lot of stress off the VE with one, so Cummins installed. Replacement 6BT diaphragm pumps go for about $60 if you shop around, and they are readily available.
Yes, never exceed 20 psi maximum.
Quality 6BT fuel pump have been purchased by others on DTR for $40 here:
http://www.usdieselparts.com/moreinfo.cfm/Product_ID/57177/sku/FP274/name/Feed_Pump
 

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If it were me I probably wouldn't exceed much more than actually 14-16 psi max if it were me.. That is considered "performance" think 8 or so is more like stock...
 
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