FW-190 D9 Electric Fuel Pumps problem

[predattak]

I noticed that my engine runs perfectly after turning off the fuel pumps (E13 E14). The fuel gauge indicates that both pumps feed the engine from both tanks at the same time EVEN when one or all of them are turned off.

 

 

I cannot control the fuel flow unless i use the fuel selector lever, manual says i should not do that instead i should control the fuel flow with the E13 and E14 breakers.

 

 

it's as if the pumps refuse to turn off once you activate them. super frustrating.

 

Can anyone replicate this on his machine?

Spawn a D9 in air

by default all the pumps will be turned on

monitor the fuel gauge for both tanks, they drain at the same time.

Good.

Now turn on or all pumps off and monitor the fuel gauge again

the same result the fuel will drain from both tanks as if the pumps where working.

 

Now you can do another thing that proves even more that this is a bug (i really hope it's not but)

Spawn a D9 coldstart

start the plane with only one pump on

fly and monitor the fuel gauge

it should drain fuel only from the tank with the activated pump

now start the second one and stop the first one

you will notice that both pumps cannot be turned off

 

you can even land the plane and stop the engine, disable all the pumps (it would be impossible to start without at least one activated)

you can start the plane just fine.. as if (and i know i'm repeating myself ) the pumps were on even when they were supposed to be off.

Edited August 14, 2019 by predattak

[grafspee]

I noticed that my engine runs perfectly after turning off the fuel pumps (E13 E14). The fuel gauge indicates that both pumps feed the engine from both tanks at the same time EVEN when one or all of them are turned off.

 

 

I cannot control the fuel flow unless i use the fuel selector lever, manual says i should not do that instead i should control the fuel flow with the E13 and E14 breakers.

 

 

it's as if the pumps refuse to turn off once you activate them. super frustrating.

 

Can anyone replicate this on his machine?

Spawn a D9 in air

by default all the pumps will be turned on

monitor the fuel gauge for both tanks, they drain at the same time.

Good.

Now turn on or all pumps off and monitor the fuel gauge again

the same result the fuel will drain from both tanks as if the pumps where working.

But flying w/o electric pumps, you are risking having fuel vapor-lock in fuel system.

 

Now you can do another thing that proves even more that this is a bug (i really hope it's not but)

Spawn a D9 coldstart

start the plane with only one pump on

fly and monitor the fuel gauge

it should drain fuel only from the tank with the activated pump

not start the second one and stop the first one

you will notice that both pumps cannot be turned off

 

you can even land the plane and stop the engine, disable all the pumps (it would be impossible to start without at least one activated)

you can start the plane just fine.. as if (and i know i'm repeating myself ) the pumps were on even when they were supposed to be off.

 

Engine has mechanicly driven pumps too, it can run on those alone too.

Electric fuel pumps help to fill fuelsystem, and do other things,but once fuel system is filled with fuel engien will start even w/o them

Running engine w/o fuel pumps, you are risking fuel vapor-lock in fuel system

I dont know how exactly fuel system looks like in fw190,but i doubt that it uses only electric fuel pumps.

Edited August 14, 2019 by grafspee

[predattak]

I understand that.

My problem is that you can't control what tank will drain first

If i start in air or i start both pumps on, that's it, i can't shut them off and start only one of them and so, both tanks get drained at the same time instead of the right order.

 

The only way to select what tanks are emptied first is to close the valve on one of the tanks with the fuel selector lever and the manual states that doing so it's not the procedure and that you're supposed to control what tanks emptied first with the electric pumps.

 

You may say that well the engine pumps are doing this but they are not because as i said before IF you start cold and only start with one pump only one tank will be used. (until you turn on the other one and after that there is no way of controlling the fuel flow)

 

You should try and see if you can replicate that if you have the module.

Edited August 14, 2019 by predattak

[grafspee]

I understand that.

My problem is that you can't control what tank will drain first

If i start in air or i start both pumps on, that's it, i can't shut them off and start only one of them and so, both tanks get drained at the same time instead of the right order.

 

The only way to select what tanks are emptied first is to close the valve on one of the tanks with the fuel selector lever and the manual states that doing so it's not the procedure and that you're supposed to control what tanks emptied first with the electric pumps.

 

You may say that well the engine pumps are doing this but they are not because as i said before IF you start cold and only start with one pump only one tank will be used. (until you turn on the other one and after that there is no way of controlling the fuel flow)

 

You should try and see if you can replicate that if you have the module.

 

You cant control drain order with electric pumps

You got fuel selector hnadle for this.

You have to set both tank position for redudnency for t/o,but after it you should switch to rear tank.

There is a good reason why fuel selector handle is so big,so you can easy check on witch tank are you running.

But if you leave fuel selector fully open, mechanical pumps will drain fuel from both

Edited August 14, 2019 by grafspee

[AJaromir]

On 8/14/2019 at 9:25 PM, grafspee said:

 

You cant control drain order with electric pumps

You got fuel selector hnadle for this.

You have to set both tank position for redudnency for t/o,but after it you should switch to rear tank.

There is a good reason why fuel selector handle is so big,so you can easy check on witch tank are you running.

But if you leave fuel selector fully open, mechanical pumps will drain fuel from both

From manual, page 33:

When the fuel selector (fuel cock) [11] is set to "Auf", both fuel lines from the forward and rear tanks are allowed to feed fuel to the booster pump. The booster pump draws more fuel than actually needed from both tanks and the surplus is routed back into the forward tank, thereby closing the valve for the forward tank. With this mechanism fuel effectively is drawn only from the rear tank as long as the engine gets enough fuel from it. When the engine pump starts to starve, the forward tank is "opened".

[Doughguy]

I guess the confusion stems from the fact that the front tank holds 230 liters and the rear 290liters.

The way i remember it to work is that if you have set the fuel selector handle to auf, indeed both fuel tanks are drained, however, as the rear tank holds more, the excess is  bein pumped back into the front one. So until youve drained 60+ liters from the rear tank, fuel is being lowered on both tanks, but only rear one shows a change.

As "auf" drains from both tanks both pumps should be activated.

If you access the tanks seperately each pump needs to be activated in conjunction with the corresponding pump to avoid air bein sucked into the system.

The later point is not simulated and is the same in the anton.

You can leave both pumps, or all 3, on all the time.

However the d9 manual describes the fuel management in 3 places and it varies partially... 

Edited December 27, 2024 by Doughguy