electric fuel pump, Where?!

[drifter001]

29 minutes ago, Fly Boomer said:

You need to figure out what's wrong with your battery or charging system or wiring before you go further with the pump.  "Starts the engine" does not mean the battery is okay.

im on a 12v system though so wouldnt that be charged. after running the engine for a bit today before scrubbing the flight, battery read about 12.4 and was reading that when i left the hanger 

[Fly Boomer]

27 minutes ago, drifter001 said:

after running the engine for a bit today before scrubbing the flight, battery read about 12.4 and was reading that when i left the hanger 

If you are seeing 12.4 OCV (open-circuit voltage) with battery unhooked, that is good.  Not a substitute for a capacity check, but good enough to run that pump.  Have you checked voltage at the pump?

[drifter001]

33 minutes ago, Fly Boomer said:

If you are seeing 12.4 OCV (open-circuit voltage) with battery unhooked, that is good.  Not a substitute for a capacity check, but good enough to run that pump.  Have you checked voltage at the pump?

I couldn’t find where the pump terminals were (wires seemed hardwired) but when I tapped the pump with a mallet and the switch in the on position, the pump started working

[Shadrach]

4 hours ago, drifter001 said:

im on a 12v system though so wouldnt that be charged. after running the engine for a bit today before scrubbing the flight, battery read about 12.4 and was reading that when i left the hanger 

What kind of battery do you have? A 12V lead acid battery is 100% charged at 12.6V. A 12V AGM battery is 100% charged at 13V. A good Skytec starter will turn the engine at low voltage levels. I don’t know how sensitive your fuel pump is to voltage, but your first step is to make sure the battery and charging system are in order.

How did the pump respond while the engine was running? My fuel pressure increases by several psi when I turn my boost pump on with the engine running.

[drifter001]

1 hour ago, Shadrach said:

What kind of battery do you have? A 12V lead acid battery is 100% charged at 12.6V. A 12V AGM battery is 100% charged at 13V. A good Skytec starter will turn the engine at low voltage levels. I don’t know how sensitive your fuel pump is to voltage, but your first step is to make sure the battery and charging system are in order.

How did the pump respond while the engine was running? My fuel pressure increases by several psi when I turn my boost pump on with the engine running.

Pump didn’t even run with engine running. Once back in the hanger I turned master on and pump on (pump didn’t work), left the switch on and tapped the pump a few times with a rubber mallet and viola, it worked

[Shadrach]

1 hour ago, drifter001 said:

Pump didn’t even run with engine running. Once back in the hanger I turned master on and pump on (pump didn’t work), left the switch on and tapped the pump a few times with a rubber mallet and viola, it worked

The brushes are warn and not contacting the commutator. Send it to Aeromotors for OH.

[hoot777]

Any good pictures of the electric pump??  I have a 68 G

thanks

[47U]

2 hours ago, hoot777 said:

Any good pictures of the electric pump??  I have a 68 G

I don’t have a pic of it installed, but this pic out of the box pic.  I put it in my buddy’s ‘68G in May last year.  I took a pic of the data plate to have reference for the logbook entry.

Found a pic of it installed in a previous MooneSpace post… pre-J, probably similar to yours.

Edited June 30, 2025 by 47U
Additional pic.

[cliffy]

Be sure to check ALL the fuel line fittings in the area and not just the two on the pump. Have found some loose from years of vibration.

 

[hoot777]

Thanks