electric fuel pump, Where?!

[wombat]

I too have a '64 M20E and had a leaking boost pump.  My plane had a dukes and I replaced it with the Weldon last summer; it was a drop-in replacement.  About $800 for a new pump from aircraft spruce plus an hour or so of A&P time.

[Carlton]

1965 M20E Electric Fuel Pump when switched to 'ON' within about 7 seconds the fuel pressure goes to zero and engine will die. Any ideas?

[carusoam]

Stay with me for a moment @Carlton...

 

There are a few interesting fuel pump diagrams....

Most Mooneys have the electric boost pump in line with the mechanical fuel pump...

Some ‘lucky’ planes are not inline...

This Possibly sounds like something is allowing fuel to backflow through a failed pump... giving zero pressure and no fuel flow to the engine.  Or leaking out to the ground...

1) Go immediately to the POH, parts manual, service books for your plane to see how your fuel pumps are plumbed...

2) look for any oneway valves...

3) clean or replace the faulty oneway valve that is allowing backflow...

4) Look Around the plane for puddles on the ground... or blue stains at the pump drains...

5) if the pump sounds normal fuel is going somewhere...

6) if the pump sounds funny, it is possible the vanes have come loose or departed the pump...

7) what do you hear when you turn the boost on?

8) do you have a fuel flow meter?  Does it get erratic during this? A sign that air is entering the line...

 

PP hypothesis only, I have only heard of this odd pump arrangement once, recently... not a mechanic.

peace and honor to our lost canopyman, who’s thread we are revisiting...  

Best regards,

-a-

[Yetti]

On 9/18/2018 at 2:37 AM, Carlton said:

1965 M20E Electric Fuel Pump when switched to 'ON' within about 7 seconds the fuel pressure goes to zero and engine will die. Any ideas?

You may have enough junk in the elec fuel pump that it is blocking fuel flow at the pump.   Check all screens.

[ArtVandelay]

You may have enough junk in the elec fuel pump that it is blocking fuel flow at the pump.   Check all screens.

Does the E have the extra screen after the fuel pump like my J does?

[Yetti]

40 minutes ago, teejayevans said:

Does the E have the extra screen after the fuel pump like my J does?

The extra screen after the electric fuel pump is because of the Duke pump exploding their plastic part and keeping those pieces from going downstream.   Subject of a SB.  I have a Weldon and also think I have a screen.

[Mark942]

A little off topic but close. I have a 64 M20E that does not have a Duke pump and also no inline filter. I am installing GAMI injectors soon as my on going referb and want to install an inline filter while torn down. Anyone know of a PMA filter that would be able to be installed. The SENCO filter in the SB is no longer in production. I purchased one from salvage, but have no way of testing this 40 year old filter before installing it.

Thanks,

-mark

[Yetti]

There is a  finger screen in the fuel servo that is supposed to catch everything before the injectors.  This is what came out mine after we brought the plane home.  Several months after a "fresh" annual.

Edited September 20, 2018 by Yetti

[Guest]

5 hours ago, Mark942 said:

A little off topic but close. I have a 64 M20E that does not have a Duke pump and also no inline filter. I am installing GAMI injectors soon as my on going referb and want to install an inline filter while torn down. Anyone know of a PMA filter that would be able to be installed. The SENCO filter in the SB is no longer in production. I purchased one from salvage, but have no way of testing this 40 year old filter before installing it.

Thanks,

-mark

Mark,

You can take it apart for cleaning and inspection.  You’ll have to measure the O ring to work out the part number.

Clarence

[drifter001]

Don’t mean to revive yet another old topic but seems like either fuel pump or the switch is acting up. Twice in the past month either nothing happens when switch is flipped or pump works then cuts out. First time it happened we accidentally had the fuel pump running when doing some ground checks when we did our panel. Started engine then pump worked after shit down. Second time was a cold plane. Flipped switch but didn’t get any noise from fuel pump. Confirmed we don’t have duke pump per log books

Edited July 13, 2022 by drifter001

[Shadrach]

3 hours ago, drifter001 said:

Don’t mean to revive yet another old topic but seems like either fuel pump or the switch is acting up. Twice in the past month either nothing happens when switch is flipped or pump works then cuts out. First time it happened we accidentally had the fuel pump running when doing some ground checks when we did our panel. Started engine then pump worked after shit down. Second time was a cold plane. Flipped switch but didn’t get any noise from fuel pump. Confirmed we don’t have drake style pump per log books

That sounds like the typical mode of failure for a dukes pump.  Not sure what a drake style pump is. Whether you have a Dukes or a Weldon, Aeromotors can either rebuild or exchange. They turned my dukes around in days not weeks. New modified pump is far superior to previous overhauls. 

[Fly Boomer]

10 hours ago, Shadrach said:

New modified pump is far superior

So you recommend new over rebuilt?  I guess it's not that much more money.

[Shadrach]

1 hour ago, Fly Boomer said:

So you recommend new over rebuilt?  I guess it's not that much more money.

I was using imprecise language. I don’t recall whether Ole (owner of Aeromotors) called it an overhaul or rebuilt. Given the number of modifications he makes to the stock Dukes pump, I would guess rebuilt to be amore accurate description but I’m not sure what the tag says.

Ole was kind enough to take some time to explain the weaknesses of the original Dukes pump and the modifications they’ve developed to mitigate said weaknesses.  He could’ve easily sold me a Weldon pump, but said that I’d spend a lot more to get the same level of reliability.  It’s been a little over three years since the installation and the pump is still performing stronger than it ever did before he laid hands on it.  I outlined my conversation with him in the thread below:

 

 

 

[drifter001]

On 7/5/2022 at 8:04 PM, Shadrach said:

That sounds like the typical mode of failure for a dukes pump.  Not sure what a drake style pump is. Whether you have a Dukes or a Weldon, Aeromotors can either rebuild or exchange. They turned my dukes around in days not weeks. New modified pump is far superior to previous overhauls. 

Sorry, I meant we don’t have a duke pump based on what I saw in the logbooks and ad list

[Shadrach]

4 hours ago, drifter001 said:

Sorry, I meant we don’t have a duke pump based on what I saw in the logbooks and ad list

So then, what do you have?  I have the IPC in front of me that covers your plane’s S/N. It calls for the same pump as mine, which is a 610153-501. That is a Mooney part number for a Dukes 1499-00-19. As far as I know, the only other option is the Weldon pump STC.

[drifter001]

7 hours ago, Shadrach said:

So then, what do you have?  I have the IPC in front of me that covers your plane’s S/N. It calls for the same pump as mine, which is a 610153-501. That is a Mooney part number for a Dukes 1499-00-19. As far as I know, the only other option is the Weldon pump STC.

I believe it’s the stc that was done on it. I was looking though my ads and it said no dukes pump installed for the fuel pump ad 

[Shadrach]

7 minutes ago, drifter001 said:

I believe it’s the stc that was done on it. I was looking though my ads and it said no dukes pump installed for the fuel pump ad 

Well, it will be easy to verify. Either way, if your problem is in the pump rather than the circuit, Aeromoters is still a good option.

[drifter001]

Question for y’all. Did the 65 have an option of either a Weldon or dukes pump? Been trying to find in the logs if or when it was converted but can’t find anything other than the A/D listings that say “do dukes pump” for the dukes pump ad 

[Shadrach]

1 hour ago, drifter001 said:

Question for y’all. Did the 65 have an option of either a Weldon or dukes pump? Been trying to find in the logs if or when it was converted but can’t find anything other than the A/D listings that say “do dukes pump” for the dukes pump ad 

In situations like these, the TCDS is often the best source of info. Looks like both Weldon and Dukes were OEM suppliers and installed in C models. I cannot speak to your specific year. Pulling the left side panel to take a look takes less than 20 minutes. It extends aft from the firewall on the left side of the wheel well. Disconnect the rod end on the left nose gear door and rotate door towards closed position to to access the inner sheet metal screws on the panel. 
 

 

[drifter001]

38 minutes ago, Shadrach said:

In situations like these, the TCDS is often the best source of info. Looks like both Weldon and Dukes were OEM suppliers and installed in C models. I cannot speak to your specific year. Pulling the left side panel to take a look takes less than 20 minutes. It extends aft from the firewall on the left side of the wheel well. Disconnect the rod end on the left nose gear door and rotate door towards closed position to to access the inner sheet metal screws on the panel. 
 

 

I did find the original equipment list that stated dukes but then it was replaced what looks like in 69. Do you know if the welding listed above would be the only part number? Trying to call around here to see if anyone has it in stock but heading home to get tools to pull the panel off

[Shadrach]

18 minutes ago, drifter001 said:

I did find the original equipment list that stated dukes but then it was replaced what looks like in 69. Do you know if the welding listed above would be the only part number? Trying to call around here to see if anyone has it in stock but heading home to get tools to pull the panel off

I don’t know. If there is an alternate number it would be by STC. Probably best to verify that there is power to the pump before you go too far down the rabbit hole of replacing it.

[drifter001]

4 minutes ago, Shadrach said:

I don’t know. If there is an alternate number it would be by STC. Probably best to verify that there is power to the pump before you go too far down the rabbit hole of replacing it.

Planning on doing just that. Didn’t have any tools on me so gonna head back to the hanger and pull the panel off. It did work initially when I got to the hanger this am but it sounded like it was either tired or low on voltage. Battery volts read 11.8 so def not a battery issue. Prior to this it would always come on strong. I really appreciate all of the help by the way 

[Shadrach]

11 minutes ago, drifter001 said:

Planning on doing just that. Didn’t have any tools on me so gonna head back to the hanger and pull the panel off. It did work initially when I got to the hanger this am but it sounded like it was either tired or low on voltage. Battery volts read 11.8 so def not a battery issue. Prior to this it would always come on strong. I really appreciate all of the help by the way 

11.8 is a dead battery. A reading of 12V is approximately 25% charged. You’re looking for 12.5V minimum.

[drifter001]

1 hour ago, Shadrach said:

11.8 is a dead battery. A reading of 12V is approximately 25% charged. You’re looking for 12.5V minimum.

Tapped the pump a few times and it did come on and currently working which is leading me to believe it is in fact the pump

[Fly Boomer]

1 hour ago, drifter001 said:

Battery volts read 11.8 so def not a battery issue

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.