Electric Fuel Pump Setup - Is this no good?

[Bo-Jangles]

There is a small electric fuel pump mounted on the passenger frame rail plumbed into the fuel line between the tanks and the mechanical lift pump. It is always on when the truck is running (power coming from fuel shut off solenoid) How bad of a setup is this? Just read on another forum that the diaphragm on the lift pump could go and then the electric pump would fill the engine with fuel wiping out the bearings in short order. How worried should I be? Looking for suggestions. Thanks.

 

[KansasIDI]

There is a small electric fuel pump mounted on the passenger frame rail plumbed into the fuel line between the tanks and the mechanical lift pump. It is always on when the truck is running (power coming from fuel shut off solenoid) How bad of a setup is this? Just read on another forum that the diaphragm on the lift pump could go and then the electric pump would fill the engine with fuel wiping out the bearings in short order. How worried should I be? Looking for suggestions. Thanks.

It is true that it can fill the crankcase with diesel, but I wouldn’t be too worried about it. You can always bypass the mechanical pump.

I had the same exact setup on my 86 when it had a 6.9 in it, but I am working on swapping a 7.3 turbo into it and while doing so I am gonna delete the mechanical pump and run a big electric one. I bought the Holley Red conversion kit from Moose Diesel. Came with most of what I need.

 

[Kdo58]

It just to help prime the system. They are usually closer to the fuel tanks.

 

[IDIBRONCO]

Mine's under the hood, but it's set up on a switch to help with priming and for emergencies. It doesn't run unless the switch is on.

 

[Bo-Jangles]

Yeah, I was wondering if my best option would be to put it on a switch. But then I'm wondering if the lift pump pressure would be affected trying to pull fuel through it when it wasn't on. Right now it's on constantly whenever the key ignition is on. Not sure what kind of electric pump it even is. The truck is new to me. 1989 F250 with 148k miles. Just trying to get it in sound reliable running condition.

 

[KansasIDI]

Yeah, I was wondering if my best option would be to put it on a switch. But then I'm wondering if the lift pump pressure would be affected trying to pull fuel through it when it wasn't on. Right now it's on constantly whenever the key ignition is on. Not sure what kind of electric pump it even is. The truck is new to me. 1989 F250 with 148k miles. Just trying to get it in sound reliable running condition.

I had issues trying to pull through an Edelbrock Diesel pump on my 90, had to delete the e pump. Had no issues pulling through the same lookin pump you’ve got that was on my 86 when it was a 6.9

 

[IDIBRONCO]

Had no issues pulling through the same lookin pump you’ve got that was on my 86 when it was a 6.9

That's the style that I have. I've had no issues running this one since the mid 2000s. It's now on it's third vehicle. Several fuel filters though. I do like to have a universal 3/8" inline filter before the E pump.

 

[Bo-Jangles]

It just to help prime the system. They are usually closer to the fuel tanks.

So is this different than an actual electric fuel pump? I'm not familiar with these pumps or much with these trucks in general. Would this kind of pump be enough to run the truck if the mechanical lift pump failed?

 

[Kdo58]

Look up russ he sells a helper pump, I use a Holley blue and removed the mechanical pump.

 

[IDIBRONCO]

So is this different than an actual electric fuel pump?

These are universal, in line pumps, not the kind that comes out on a vehicle from the factory.

Would this kind of pump be enough to run the truck if the mechanical lift pump failed?

I have mine partly for priming, and partly for emergencies. I have used it once when I had a mechanical lift pump fail. I drive straight home, to Auto Zone to buy a new mechanical one in the morning, and then to the shop where I was working to install the new mechanical pump. I stayed in town and didn't go over 45 MPH. That was for no more than 10 miles and probably closer to 6 or 7 miles. So, at least in some instances, they can be used for an emergency. The problem you can run into is that the lower volume of fuel that the cheaper e pumps put out can affect your engine timing and cause you to not get full power out of your engine.

 

[Bo-Jangles]

Got it. I guess at the moment I won't worry about too much (have other things to straighten out on this rig). I'm a worry wort and always fear the worst, lol. Thanks for the input and replies.

 

[Noiseydiesel]

Electric fuel pumps are designed to push fuel.
NOT pull it.
They work best when lower than the tank and can go to not working at all when mounted in the engine bay.
Electric pump can push fuel up to 11 feet in the air and that was cheap pumps back in the day.

 

[nelstomlinson]

My Brown Crewcab has been set up that way since before I got it. I did have a mechanical pump failure that may have leaked into the block. Fortunately I caught it before there was any obvious damage, changed the pump and the oil and carried on.

Next fuel pump failure I plan to bypass the mechanical pump entirely and go to a Walbro, mounted down on the frame rail, where the Brown Truck has its little piddly pump. Haven't had a failure since I put the Walbro on the shelf in the shop.

 

[KansasIDI]

Haven't had a failure since I put the Walbro on the shelf in the shop.

Musta scared off old Murphy…

 

[Lumberjackchuck]

I run a Holley black along the frame and deleted/blocked off the mechanical pump. Been running it for about 2 months w/ no issues. But I always carry extra fuses in the truck just in case.

Personally, I like not having the mechanical pump. It makes purging air out of the fuel lines/maintenance easier when replacing fuel filters and you don’t have to worry about the failure you described.