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I am guilty of abusing the electric fuel pump in my a/c.  The switch for the electric fuel pump in my '67C is way over to the left in the row of toggle switches at the bottom of the panel.  It is hidden from vision by the left portion of the yoke that usually has my left fist around.  I really just can't see it from my normal position.    I usually remember to switch it on at the times when we are supposed to, but it amazes me how often I forget to turn it off.   Occasionally I'll turn it on to switch tanks, then notice many minutes later that I forgot to shut it off because I got distracted by something else. 

I'm tired of abusing that poor thing so I'm thinking about moving the position of that toggle switch to a more visible location.  I'm also thinking about connecting it to a toggle switch with a light on the end.  Any thoughts?   I stopped by an auto parts store the other evening and they have a nice selection of what seem to be rugged, illuminated, toggle switches with high amp ratings (e.g. 30 A).

Thanks.

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Just now, Fred_2O said:

I am guilty of abusing the electric fuel pump in my a/c.  The switch for the electric fuel pump in my '67C is way over to the left in the row of toggle switches at the bottom of the panel.  It is hidden from vision by the left portion of the yoke that usually has my left fist around.  I really just can't see it from my normal position.    I usually remember to switch it on at the times when we are supposed to, but it amazes me how often I forget to turn it off.   Occasionally I'll turn it on to switch tanks, then notice many minutes later that I forgot to shut it off because I got distracted by something else. 

I'm tired of abusing that poor thing so I'm thinking about moving the position of that toggle switch to a more visible location.  I'm also thinking about connecting it to a toggle switch with a light on the end.  Any thoughts?   I stopped by an auto parts store the other evening and they have a nice selection of what seem to be rugged, illuminated, toggle switches with high amp ratings (e.g. 30 A).

Thanks.

Keep in mind that the existing switch doubles as a circuit breaker, so you would need to add a circuit breaker if using a regular switch.  

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Just now, takair said:

Keep in mind that the existing switch doubles as a circuit breaker, so you would need to add a circuit breaker if using a regular switch.  

Rob thanks for your post.  That is weird, there are no markings or other indication that it is a circuit breaker.   It feels like just another toggle switch.  If it were a circuit breaker, wouldn't it have to be placarded as such?   I'll have to verify that it is actually a circuit breaker then ask my A&P to recommend a fix if so.

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After a few flights in my M20C...

i found my procedures needed adjustment... @1k’ AGL verify... gear up, flaps up, fuel pump off...

When switching tanks... I didn’t use the fuel pump, flop the valve, verify the fuel pressure... done...

Following the procedure is always a good idea... pump on, valve flop, pump off....  at the moment something gets in the way of this 10sec procedure, the pump will be left on until landing...

 

All the switches on the lower edge of the panel are CB switches.  You can put your head under there to see them... or check the wiring diagrams and parts catalog for the cryptic notes that indicate the CB...

 

PP thoughts only, not a mechanic or CFI...

Best regards,

-a-

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I think Fred probably forgets it more during tank swaps than immediately after take off.

I like Andy’s suggestion of an indicator lamp. In my F the lo/hi vacuum annunciator is no longer used since I pulled the vacuum system.

I also like his checklist recommendation. When I swap tanks, my flow is pump on, switch tanks, pump off, check pressure. I should probably add an in flight checklist for tank swaps but the flow has worked fine for 28 years. As has switching to the Weldon continuous duty pump for when I do the knucklehead thing and get distracted.



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We only use the electric FP for starting.  Given its typical life span, I'd almost feel better about switching it on in an emergency than assuming it's working as a redundant system. It's my great hope that the Aeromotors OH that was just completed on mine makes it a viable unit for take off and climb out.  This is the 3rd time our pump has been out of the plane in the last 15 years. Fingers crossed...

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1 hour ago, Marauder said:

I think Fred probably forgets it more during tank swaps than immediately after take off.
 

I think you're probably right.  In that case, like Anthony said, he shouldn't use the pump for tank swaps, just monitor the fuel pressure.

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Yep, mostly I forget during tank change overs because after I get it switched I immediately look at the engine monitor and watch fuel pressure or any other changes.   I really like the indicator light idea.  Easier to do too.

It is odd that if the entire row of toggles below the panel on the pilot's side are all circuit breaker type switches, the POH mentions nothing about that fact that I recall.   What happens when there is a short and one of those trips?   How would you know???   What is the reset procedure?

 

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Fred,

When overloaded, The switch toggle moves to the off position, via a spring.

Reset is by turning it back on.

Do it once, by the CB rule...

A simple LED would make a great addition... for things that should be temporary. And cost a lot when over used.

One light attached to a few switches won’t be enough of a reminder to turn the pump off...

PP thoughts only,

-a-

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I do not use the fuel pump when switching tanks in my C. I simply bend down, grab the switch in the middle and turn it 180°. There may or may not be a momentary pause at the OFF detent halfway there. Except the couple of times I have purposely run the tank dry first, there has not been even a gurgle, burp or wiggle of the FP needle.

My switch is high and to the right, next to the radio stack and is a circuit breaker switch, just like the rest of the row. I use it mainly to build fuel pressure for starting the engine when cold.

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28 minutes ago, Fred_2O said:

Yep, mostly I forget during tank change overs because after I get it switched I immediately look at the engine monitor and watch fuel pressure or any other changes.   I really like the indicator light idea.  Easier to do too.

It is odd that if the entire row of toggles below the panel on the pilot's side are all circuit breaker type switches, the POH mentions nothing about that fact that I recall.   What happens when there is a short and one of those trips?   How would you know???   What is the reset procedure?

 

Like Anthony said, it flips to the off position. I had it happen with my landing light. Had some work done on the plane and when they buttoned it back up they had left the wire for the landing light too loose and it melted to the exhaust and flipped the switch. Tried turning it back on and it flipped back off, left it that way and investigated once on the ground.

I don't turn it on for switching tanks in my plane either, switch tanks, watch fuel flow on the EDM, and fly on.

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Consider...

Having a carburetor can make a small time difference.

How much time can be allowed before anything changes...

The carb has a fuel reservoir with a float controlled valve for controlling the level of fuel...

Fuel injector systems don’t have a reservoir other than the fuel lines themselves...

Fuel pressure indications are a bit different as well... Carb 6psi, FI 35psi?

PP thoughts from fuzzy aged memories...

Best regards,

-a-

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2 hours ago, carusoam said:

One light attached to a few switches won’t be enough of a reminder to turn the pump off...

Maybe not for you, but it sure works for me.  I rarely forget to switch the pump off, and typically will notice higher fuel pressure first, but the indicator light has been effective as well.

I also only use it on engine start. 

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30 minutes ago, neilpilot said:

Maybe not for you, but it sure works for me.  I rarely forget to switch the pump off, and typically will notice higher fuel pressure first, but the indicator light has been effective as well.

I also only use it on engine start. 

To be more specific...

If you have one alert attached to the pump being on, and the landing light, as somebody mentioned above...

The advisory would be on all the time... and not act as a reminder of the FP being left on...

Sorry for the confusion that went with that...

Best regards,

-a-

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6 minutes ago, carusoam said:

To be more specific...

If you have one alert attached to the pump being on, and the landing light, as somebody mentioned above...

The advisory would be on all the time... and not act as a reminder of the FP being left on...

Sorry for the confusion that went with that...

Best regards,

-a-

Well as posted above it's my 65C that has a single indicator light for 3 items (fuel pump, landing light and pitot heat).  I can see there might be an issue for a pilot that leaves the light and/or pitot heat on with some frequency.  I do not, and that single indicator light has worked well as a reminder to switch off any or all of those 3 items.

 

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A few questions.

Why does a carbureted C model need a fuel pump turned on for starting?  The fuel bowl should still be full from the last shut down.  A few pumps of the throttle should be the only thing required.

Why do some many use the fuel pump when switching fuel tanks?  With your engine at run up power, turn the fuel selector to OFF, note how long the engine runs before stumbling and beginning to quit.  If you can switch tanks in less time than that, you shouldn’t need the pump on.

Clarence

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4 minutes ago, M20Doc said:

A few questions.

Why does a carbureted C model need a fuel pump turned on for starting?  The fuel bowl should still be full from the last shut down.  A few pumps of the throttle should be the only thing required.

Why do some many use the fuel pump when switching fuel tanks?  With your engine at run up power, turn the fuel selector to OFF, note how long the engine runs before stumbling and beginning to quit.  If you can switch tanks in less time than that, you shouldn’t need the pump on.

Clarence

Can you explain how the fuel pump would be relevant in this situation? Wouldn't the fuel be exhausted regardless if the pump was on or off in the slow selector turn in the runup situation described above? 

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1 hour ago, M20Doc said:

A few questions.

Why does a carbureted C model need a fuel pump turned on for starting?  The fuel bowl should still be full from the last shut down.  A few pumps of the throttle should be the only thing required.

Why do some many use the fuel pump when switching fuel tanks?  With your engine at run up power, turn the fuel selector to OFF, note how long the engine runs before stumbling and beginning to quit.  If you can switch tanks in less time than that, you shouldn’t need the pump on.

Clarence

If I'm just making a lunch run, there's often plenty of fuel, just pump the throttle and go. But if it's been several days or longer, the fuel pressure needle is resting on the peg, so I run the pump until fuel pressure stabilizes and turn it off. Pump the throttle a couple of times and start her up; in cold weather I will pause to wind and set the clock to give the cold fuel time to vaporize. 

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3 hours ago, M20Doc said:

 

Why does a carbureted C model need a fuel pump turned on for starting?  The fuel bowl should still be full from the last shut down.  A few pumps of the throttle should be the only thing required.

 

It doesn't need the pump to start, but running the pump ensures, for safety, that it hasn't failed by listening to its sound and by observing the fuel pressure gauge.  

With the engine running, I can't hear the electric pump run over the engine running.  Also, my engine driven fuel pump pressure is about 4-5 psi, the electric pump is 5.5-6 psi. There are times I can't really tell the difference.

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