Question for Facet Duralift owners

[tbrumm]

Last fall, I installed a Facet Duralift electric lift pump on the right side inner fender in the engine bay of my truck. It has worked great. At the time I installed it, I also installed an electric Autometer fuel pressure gauge in a dash pod. The gauge sender is remotely mounted to the right inner fender and fed by a braided stainless hose tee'd into the filter head at the fitting for the filter restriction sender. The filter restriction sender is still in place and functioning. Up until about a month ago, the fuel pressure gauge read a rock steady 7 psi when the pump was on. Then one day, the needle on the gauge began to "flutter" while the pump is running, and pressure dropped to about 3 psi, and it has been that way ever since. At heavy throttle, I can bottom out the gauge to zero, but the truck does not starve for fuel and the restricted filter light never comes on. The first thing I thought was my fuel filter was getting dirty, so I changed it. That made no change. I contacted Autometer to inquire about a bad gauge sending unit. The rep. told me those usually fail completely rather than a partial fail. I have a mechanical fuel pressure gauge that I am going to hook to the filter head to see what gives. However, I wanted to ask a question to all those who have the Facet Duralift fuel pump: Is the clear bowl supposed to be completely filled with fuel while the pump is running? I noticed the bowl on mine is completely full while the pump is off. When the pump is running, the bowl is only about 1/2 full with fuel - is that normal? Thanks for your input.

 

[The_Josh_Bear]

Mine is mounted vertically on the frame down between the vac pump and radiator, and it always has maybe 1/3 bowl of air in it. Doesn't seem to matter for fuel supply.
My supply pressure is about the same as yours is now, anything near WOT drops it to zero. Pretty annoying. And at idle with the engine hot it can be around 10psi. That big difference in inlet pressure messes with the timing a little and it ****** me off.

How did you test the pressure restriction sender to verify it's working?

 

[DrCharles]

Up until about a month ago, the fuel pressure gauge read a rock steady 7 psi when the pump was on. Then one day, the needle on the gauge began to "flutter" while the pump is running, and pressure dropped to about 3 psi, and it has been that way ever since

OK, so something changed and you need to find out what! Inlet restriction, pump failure, or as you already thought of, the gauge could be lying.
First, connect a mechanical pressure gauge and verify that the pressure is really only 3 psi and fluttering.

If so, I suspect that the pump's internal pressure regulator (bypass valve) is stuck open. I don't think it can be serviced though. Is your pump still in warranty?

 

[tbrumm]

Dr. Charles - Yes, I believe the pump is still under warranty. More diagnosis is in order! I was starting to think I had a fuel line restriction since the pump bowl is only about 1/2 full when the pump is running.

The Josh Bear - I believe the filter restriction warning light comes on briefly as a self test when starting the truck.

 

[Clb]

Ok
Mine runs with air in the bowl, on long full throttle runs the f r lamp will show up but I do not feel starvation.
Hope someone verifies if the effing pumps are rated for ENOUGH flow, cuz I jumped on the bandwagon due to the tech article here.

 

[tbrumm]

I hooked the mechanical gauge to the filter head and got a rock steady 5 psi. Hooking the Autometer gauge back up, I get a fluttering needle at around 3 psi when it used to be a solid 7 psi. I think the gauge or the sending unit is wacked. My next thing to check is the gauge power lead and ground.

The Facet 40222 pump specs state maximum pressure is 9-11.5 psi. Could there be a 4 psi pressure drop from the pump outlet, through 2 feet of 3/8" fuel hose, through the filter and filter head? I suppose that is possible as the pump must "pressurize" the filter and fuel is also flowing out of the filter head continuously.

 

[tbrumm]

Ok
Mine runs with air in the bowl, on long full throttle runs the f r lamp will show up but I do not feel starvation.

Clb - thanks for confirming the air in the bowl. Is your pump also mounted in the engine bay?

 

[DrCharles]

The Facet 40285 and 40222 are rated at 33 gph. That is WAY more than enough to feed a stock IDI. Mine is mounted on the right inner fender too.

Speaking of power and ground connections, something else to check is the voltage at the actual pump leads. I'm not sure about these pumps, but the rotary in-line or in-tank pumps used in gasoline fuel injection systems are very sensitive to supply voltage and draw a lot of current when working hard.

4 psi sounds like a lot of pressure drop, but that will depend on flow of course. At idle there is hardly any fuel going into the engine, and the return line has a restrictive orifice. These pumps are supposed to be putting out 33 gph WHILE also providing the minimum rated output pressure, so since they are never called upon to deliver that much fuel the pressure should be above the minimum too. Can you tee the working mechanical gauge into the output of the pump before it goes through the filter?

 

[laserjock]

Mine also has air in the bowl. Just FYI. I had a fuel pressure gauge under the hood but my gauge vibrated itself apart. The liquid filled gauge lied to me. Felt like an idiot there. No way for me to know if it’s starving because I never hooked the filter light back up.

 

[laserjock]

The Facet 40285 and 40222 are rated at 33 gph. That is WAY more than enough to feed a stock IDI. Mine is mounted on the right inner fender too.

Speaking of power and ground connections, something else to check is the voltage at the actual pump leads. I'm not sure about these pumps, but the rotary in-line or in-tank pumps used in gasoline fuel injection systems are very sensitive to supply voltage and draw a lot of current when working hard.

4 psi sounds like a lot of pressure drop, but that will depend on flow of course. At idle there is hardly any fuel going into the engine, and the return line has a restrictive orifice. These pumps are supposed to be putting out 33 gph WHILE also providing the minimum rated output pressure, so since they are never called upon to deliver that much fuel the pressure should be above the minimum too. Can you tee the working mechanical gauge into the output of the pump before it goes through the filter?

Remember, it’s not just fuel consumed, its consumption plus the return fuel that cools everything so 33 gal per hour may not be as much as it sounds.

 

[tbrumm]

4 psi sounds like a lot of pressure drop, but that will depend on flow of course.Can you tee the working mechanical gauge into the output of the pump before it goes through the filter?

That is probably the next thing I will try.

 

[Clb]

Tbrumm
My pump is on the frame down by front tank.

There was someone who installed a poppet \restrictor in the returns to up the feed flow\pressure....
Now WHERE is that info???hmmm
aint found it but....

i bumped the threads I marked for this as research...tagged ya also.

 

[tbrumm]

Clb - thanks for the tags - that is some interesting reading right there.