Primer Solenoid Testing?

jsharkey · #1 05-04-2008, 01:58 PM

I'm testing my electrical system and was expecting a click or a clunk when I energized the primer solenoid but can't detect anything. Everything checks out with a meter. Just no indication that it is functioning. Anyone else got any experience with them?
Jim Sharkey
RV6 - Wiring

Bob Axsom · #2 05-04-2008, 02:31 PM

When you use the system you can verify that it works just with engine starting ease. You can do a two person required test where you turn on the aux. pump to pressurise the system with a primer line disconnected at a cylinder and verify that no fuel comes out, press the primer momentary switch, verify that fuel comes out, release it and verify that the fuel flow stops but I just did the same test you did and went with it as verifying port opening with power application. If operation proved there was a problem I would have proceded with trouble shooting but that didn't happen - the primer solenoid worked as expected.

Bob Axsom

vansrv8 · #3 05-04-2008, 03:07 PM

Mine (from Vans) makes a pretty loud clunk when energized...

jsharkey · #4 05-04-2008, 03:28 PM

Quote:

Originally Posted by vansrv8

Mine (from Vans) makes a pretty loud clunk when energized...

Thanks - that's what I expected. I need to do some trouble shooting.
Jim

pierre smith · #5 05-05-2008, 05:49 AM

Hi Jim, we also wired our primer pushbutton from the fuel pump switch so that it's only supplied with power while the fuel pump is on. This way you can't flood the engine in flight if the primer is accidentally pushed to on.

Regards,

N395V · #6 05-05-2008, 06:58 AM

Quote:

Originally Posted by jsharkey

Thanks - that's what I expected. I need to do some trouble shooting.
Jim

Mine is silent but works just fine.

Kahuna · #7 05-05-2008, 07:32 AM

Quote:

Originally Posted by N395V

Mine is silent but works just fine.

Im not sure I have ever "heard of a silent solenoid". Seriously. All solenoids of this type should click. You should hear it and feel it.

Now you might not hear it over other stuff like gyros spinning up or fuel pumps running. But if you just testing the solenoid, that thing should be heard from 50 feet away.

Its just a big relay that uses electromagnets to activate big contactors. When the contactors hit, its noisy, at least it should be. Even the tinyiest of relays that can fit on your finger tip, click and make noises. Perhaps micro relays cant be heard by the humad ear unassisted. I dunno.

jsharkey · #8 05-05-2008, 09:32 AM

Quote:

Originally Posted by pierre smith

Hi Jim, we also wired our primer pushbutton from the fuel pump switch so that it's only supplied with power while the fuel pump is on. This way you can't flood the engine in flight if the primer is accidentally pushed to on.

Regards,

Yes - that's the way it's wired. I disconnected the pump to test the solenoid because it creates a racket when working dry. Hopefully it's quieter with fuel in it.

Jim

647jc · #9 05-05-2008, 09:52 AM

I have a similar configuration and also disconnected my fuel pump to verify the primer solenoid activates. Yes, I definitely hear a clunk when I push the primer button, not as loud as the master or starter solenoid but a definite clunk.

I assume your wiring has 12 volts coming to the primer button from the switch that turns on your fuel pump. Also, the primer button should then provide 12 volts to the primer solenoid when the button is pushed. The other side of the solenoid should be connected to ground. It?s possible the primer solenoid plunger is stuck in which case you would not hear a clunk. You can verify the wiring by verifying the magnetic coil of the solenoid by holding a small screw driver close to the solenoid and have someone push the primer button. You should be able to detect the solenoid becoming magnetic when the button is pushed. If the solenoid becomes magnetic and still no clunk, you should be able to disassemble the primer solenoid valve assembly and determine if the plunger is indeed stuck and possibly free it up.

jsharkey · #10 05-05-2008, 10:47 AM

Quote:

Originally Posted by 647jc

I have a similar configuration and also disconnected my fuel pump to verify the primer solenoid activates. Yes, I definitely hear a clunk when I push the primer button, not as loud as the master or starter solenoid but a definite clunk.

I assume your wiring has 12 volts coming to the primer button from the switch that turns on your fuel pump. Also, the primer button should then provide 12 volts to the primer solenoid when the button is pushed. The other side of the solenoid should be connected to ground. It’s possible the primer solenoid plunger is stuck in which case you would not hear a clunk. You can verify the wiring by verifying the magnetic coil of the solenoid by holding a small screw driver close to the solenoid and have someone push the primer button. You should be able to detect the solenoid becoming magnetic when the button is pushed. If the solenoid becomes magnetic and still no clunk, you should be able to disassemble the primer solenoid valve assembly and determine if the plunger is indeed stuck and possibly free it up.

Good idea to check if it's magnetized. I'll do that before tearing things apart.
Thanks
Jim Sharkey

PS - Is the solenoid polarized? Could I have it wired backwards? The leads were the same color with no one obviously meant for ground.