Fuel Pump Enable?

[singlewc]

My 81 Air Cooled has sat for most of the year. Recently started it up to bring it into the garage for some work, and noticed that when I turn the key on, the fuel pump starts up.

Near as I can recall, the pump is not supposed to come on until I start to crank the engine, which is what the relays are supposed to do.

It sat for a few days, and then I turned on the key again, and it most surely is the fuel pump, as I could hear the fuel rushing through the input and out to the return line.

Am I correct, that this is not supposed to happen? Any suggestions? I am guessing a relay has failed, but figured to ask before I went too far in case I have forgotten the normal 'sounds of my van' <g>

Thanks,

John

[mightyart]

The fuel pump comes on when the key is turned on not just when cranking.
Otherwise it would stall when you stopped cranking.
Same thing with push starting, or poping the clutch to start it.
turn the key to on, get it moving, push in the clutch, put it in gear, let out the clutch, should start without the key going to the start position.

[germansupplyscott]

[mightyart]

Yep Scott's right, I thought you ment When the key was turned to the start position.
You have to have some suction to move the Flap on the afm.

[singlewc]

[JunkYarDog]

My 85 cycles the pump when I turn the key to the on position just before I start the engine. I would think it would need to do this to build pressure just prior to starting. Otherwise, the engine would be waiting for fuel pressure to rise before it would start. I know it doesn't take long for the pressures to get up but it makes sense. Like I siad mine cycles, it runs briefly twice then stops until the engine is started.

[tencentlife]

Digi -jets and -fants do it that way, JYD, but the earlier AC L-jets with a double relay required a tap of the starter to spin the pump for a second. A contact in the AFM would keep it running when the motor starts.

No need to boost pressure before starting, either; the system holds base pressure when shut off. The pump can raise it to full pressure before the engine even makes a half-turn.

[JunkYarDog]

Just my 2 cents, and in this case cycles

[Bambus]

if mem serves, the airhead double-relay gets its signal from the starter solenoid-- pump fires w/ crank-on. Ergo check all those starter connex first (cleanliness, tight, etc)

Those double relays are stout as hell. I replaced one unnecessarily on the '81-- was the starter