I have a 1988 ford F-150 with a 302. I am going to make a EFI to carb swap. The truck has two gas tanks (each with a low pressure pump) a high pressure pump on the rail under the drivers seat. I am going to put a fuel pressure regulator in the line coming from the tanks. Was wondering if I need to do away with the high pressure pump or if I need to keep it. From what I have googled, low pressures put out (this varies greatly from 4 to 12 psi) and the high pressure about 35-45 psi. Should I take out the high pressure pump and run a non return regulator or keep the high pressure pump and run a return regulator. New tanks and in tank stuff. Also, I understand that when I turn the key to start the high pressure pump comes on for a second or two and then shuts down. What is the mechanism that does this? Thanks

 

I know this is not what you asked but I would strongly advise against an EFI to carb change over. I see no single advantage to it.
To answer your last sentence, the computer is what triggers the pumps to energize for a few seconds when you turn the key.

 

I hear ya raski and support what you say. There is nothing better than fuel injection up to a certain point. I mean, who wouldn't want a xl, short bed, 302 M5od in great original condition? The truck that I am working on has 396K miles and has been sitting since 2005. While I believe it was well taken care of (everything that I have torn apart so far indicates original factory) it is really badly worn, heat beat and brittle. There are three reasons that I'm choosing the path I chose. I'm not going to the expense of putting it back original, I'm too poor and too cheap (I know, not much of an excuse, but it's the truth), I'm trying to build a very basic vehicle that I won't have to run to Amazon or Ford every week for parts, and I've found what I believe is some kind of "stop leak" in the radiator and block. It stopped flow in the radiator and completely blocked the thermostat. I haven't found any water in the oil, but there is a reason for that much additive. I have most of the parts I need to make the change at hand. Just wanted you to understand that I'm not jumping off the EFI to carb cliff without any, what I call, valid reasons. I'm not fooling myself thinking I can gain more hp. If I haven't incurred your rath too much, do you think a Hybrid of computer and basic (points) ignition and vacuum advance, where I retain pump stop and original gauges on the dash is possible? Also, what thinks you about the pressure regulator? I value your knowledge, thanks

 

I have to agree with raski on this one, why change over? You did not state what the problem is with your current EFI system. Is it not running because it doesn't work? Run like crap? Or it has sat for so long you feel it won't work? My truck has 538k miles on it. Outside of replacing a few pumps and sensors, it works great. Currently your truck is controlled by the computer. You might open up a whole new can of worms.

 

Thank you for your reply. Feel like I kinda lit a fire under the "EFI" boys. I didn't mean to offend. I stated my reasons for the swap in my original post. Someone graciously replied with older thread and reply by IIIeo and wde3477. raski replied with what makes the fuel pumps delay. Any info on retaining the original working of the fuel pumps and gauges without the computer, (timer for the fuel pump and voltage for the gauges), I guess is the can of worms I'm looking to open. Any info would be appreciated. Thanks

 

I'm not an "EFI" boy, nor was I offended. Just trying to let you know that it's not as easy as putting on a carb and intake. There is more to it. And you may end up spending more than you think.

 

Ok, thanks.