2005 150hp TXR

[Mr. smiley]

I am new to this motor. Just got it running this week . Sounds good. What is the noise I hear when key is turned to on position and then to off position? Sounds like a pump noise coming from inside transom area.

[chuckpolzin]

i was wondering same thing on my 2015 f175. i believe its something w electronic throttle valve control. totally normal i hope. mine takes a few seconds to go away when i turn off

[Nautical]

High Pressure fuel pump runs for about 5 seconds (key on) to pressurize fuel rail. Normal condition, worry when you don't hear it.

[99yam40]

fuel pump should not be running after/when turning off key switch.
Idle air control valve should be making some noise when resetting for next start up when key is turned off maybe

[boscoe99]

I am a bit confused.

The OP has a two stroke model by his definition of the motor. I don't think it should be making any noise when the key is turned on. Perhaps he is pushing the key inward causing the electric choke solenoid to be activated.

Now for the guy with the F175 EFI several things happen when the key is turned to the on position. The electronic throttle valve (ETV) cycles, the fuel injectors pulse and the electric fuel pump runs for several seconds to build up fuel pressure in the fuel rail. The ETV may also cycle when the key is turned off.

[seahorse5]

Mr.Smiley,

Is your motor an F150TXR or a 150TXR? If you are not sure, is it a V-6 150 or a 4 cylinder 150 ?

If it is an F150 which has only 4 sparkplugs, a clicking or clattering noise that you hear when you turn the key to OFF is the idle speed control ( ISC ) cycling to be in position when the motor is started up again.

[Mr. smiley]

It is a F150 TXR 4 cylinder. When I turn the key to the on position for 2-3 sec. and then to off position there is a definite loud pump like noise that runs aprox. 2 sec. I have not tried to track the noise down. Boat is 30 miles away. The noise did not seem like it came from the motor, more like inside starboard transom area. The boat has Lenco trim tabs. Could these have something to do with this noise?

[boscoe99]

The F150 fuel pump will run for several seconds upon the key being turned on but if you hear it you have damn fine hearing.

Lenco and other tabs sometimes have an autoretract function when the key is turned off. Maybe they default back to their former position when the key is turned on.

[rodbolt17]

if the engine was running, you will hear the ISC.
just cycling the key you wont as its already at 100%.

most lenco tabs,mine included, have an auto retract function.

try this next time.
turn the key on.
lower the tabs.
turn the key off.
watch the tabs.
used to be the auto retract feature was an option.
I don't think you can buy a control unit without it now,

[Mr. smiley]

Worked on the boat yesterday and the noise is the lenco trim tabs auto retracting. Thanks for all your feedback.