electric fuel pump conversion

Ok, so I am looking at replacing my mechanical pump with an e pump. The mechanical pump has an in , out, and fuel return connections. When you replace with an e pump, do you simply plug off and eliminate the fuel return line?

93 E350 Club wagon 7.3 idi NA

Gotta be 6 e pump threads plus one in the tech section.
Read them FIRST

Your mechanical lift pump shouldn't have any return lines going to it. It's just an in and out hook up.

this is taken from the Chilton repair manual. Note line 3. , and 9.

That’s why I only use Chilton and Motors manuals as a last resort. The mechanical lift pump on 6.9 and 7.3 has 2 lines. The filter head has 3 lines.

Lots of info in this thread as well. The subject "truck" is a van configuration so it might have some helpful details about van applications as well.

https://www.oilburners.net/threads/biting-the-bullet-converting-to-electric-fuel-pump.87176/

lonnoid said:

Ok, so I am looking at replacing my mechanical pump with an e pump. The mechanical pump has an in , out, and fuel return connections. When you replace with an e pump, do you simply plug off and eliminate the fuel return line?

93 E350 Club wagon 7.3 idi NA

Click to expand...

Since you have a van, do yourself a favor and delete the stock filterhead as well. The mech lift pump and filter head take up way too much room in that engine bay, and it'll be 1000x better if you install your e-pump and filters on the frame rail. Here's a write-up of my setup on the tranny crossmember, but rail mounting would be fine as well:

https://www.nickpisca.com/diesel/fu...ed-e-pump-sensors-and-frame-rail-dual-filter/

Video:


The process is really simple: Just install your e-pump after the selector valve. You can use diesel-rated fuel hose to replace the hard lines. You just need a bleeder at the high-point of the system, so I installed a simple schrader valve on an extension up by my radiator, so I can hold a cup under it to catch any fuel that comes out when if I need to bleed the air out of the system. Since you will have an e-pump, it's super easy to bleed the air, just turn on the pump. Some guys run a switch that they turn on before they start the van, and other guys (like me) just ran a relay from key-on power, so it turns on when I turn the key.

Since this thread it moderately active, how about a " different" idea that came in passing the other day

T's at both the inlet and outlet side of the mech pump, and a switched e-pump to prime the system. Using a check valve so as not to push fuel back through the mech pump obviously, I can't see any reason this wouldn't work.

Any thoughts or arguments?

Yep, it was done recently. Reports are it works pretty well though he lets them run in parallel all the time.

He describes the components he used here:

https://www.oilburners.net/posts/1047333/

and discusses the installation further in the thread. I don't know if he discussed his plan earlier in the thread.

Here's a pic of his layout.

https://www.oilburners.net/posts/1056524/

Ah yes, that's exactly what I was thinking. I suppose time will tell how he likes it in the long run

I did the conversion last year entirely using tue newest tech article.

The article included everything I needed including fittings, part numbers of the blocking plate, how to safely install it electrically with relays and everything.

I love it!

I do need to remember to replace the solid black fuel line with clear, however

BR3 said:

Since this thread it moderately active, how about a " different" idea that came in passing the other day

T's at both the inlet and outlet side of the mech pump, and a switched e-pump to prime the system. Using a check valve so as not to push fuel back through the mech pump obviously, I can't see any reason this wouldn't work.

Any thoughts or arguments?

Click to expand...

I did exactly this with my setup except that the e-pump is only triggered off the high-idle circuit, so it runs every morning incase air got in somehow. I'd like it on a switch too but if I have to I can move the trigger under the hood to the FSS on the side of the road so it's running with the key on.

I LOVE this setup, as you mentioned don't forget the check-valve and you're golden. The E-pump already has built-in check valves so you only need one as you said. I also eliminated the stock fuel header and rigged up a small aluminum manifold that doesn't leak or let air in. Had to make room for my BHAF intake pipe on the turbo!

BTW the reason I did this even though I already had the e-pump(Facet Duralift 9psi), was because it just doesn't have the flow to keep up at WOT. Inlet PSI drops to 1psi which affects the timing of fuel delivered. Motorcraft lift pump fixed that and I still have priming ability. Plus if either one fails I always have a second pump onboard, already plumbed in, so I don't take a diesel bath changing it on the side of the road.

That's good to know, and I may even steal your idea on the high idle as the signal as well, I hadn't considered that until you mentioned it. It really seems like a great idea given that it would keep the pump running with the rest of the "automatically controlled" factory startup systems.

Or wire it into the glow plug bypass type setup...

BR3 said:

T's at both the inlet and outlet side of the mech pump, and a switched e-pump to prime the system. Using a check valve so as not to push fuel back through the mech pump obviously, I can't see any reason this wouldn't work.

Any thoughts or arguments?

Click to expand...

That sounds like a good idea, if you're going to buy an expensive electric pump that can actually replace the stock mechanical pump. I'm too cheap to go that route, and I really don't like depending on electric stuff, so I bought a $50 electric pump and put it in the line between the mechanical fuel pump and the selector valve. It will push fuel through the mechanical pump to prime the lines, and it will let the mechanical pump suck fuel through it when it can't keep up.