I've seen lots of posts that recommend bench testing a fuel pump, but I was not able to find one that described how to perform the test. I've got a couple that I need to test, but I've got no idea how to do it without completely ruining it. Could anyone tell me how to get this done without messing up a potentially good pump?
Thanks!
Full Version: Bench Test Fuel Pump
You could hook up hoses like the factory arrangement as on a car. You would have an intake hose and a return hose that you could arrange with a gas can. You probably would want a fuel filter. 12 volts to the pump should power the pump to allow observation of it's pumping ability and capacity. I think these pumps use the fuel to cool the pump so don't run the pump dry for an extended amount of time, for example, you could probably touch 12 V and ground to the pump electrical connections to see if the motor runs but don't leave it connected. The usual precautions about working around gas and sparks apply.
Awesome! Thanks for the quick reply. So there is no "positive" or "negative" terminal on the pump?
No problem with positive and negative if you don't care which direction the pump turns and if you don't care if the pump works after running it backwards and dry.
Look at the pump.
Bosch and all of the others I've seen others have the terminals marked.
Don't run a pump dry, the pump needs gas as a lubricant to prevent damage to the bearings and to the pump rollers and roller contact surfaces.
In the car, gravity primes the pump which is why it's easy to put a pump on a car and fill it with gas before starting it.
On the bench, it's tricky to ensure gas is in the pump before you start. Maybe a hose with a siphon squeezbulb between the gas container and the pump to fill the pump before you start. Squeeze the bulb to fill the pump, start it up. Be sure to have a second container to catch the gas as it dumps out of the primed pump. This also cleans spiders and crap out of the pump.
In our systems, it's the pressure regulator valve downstream from the injectors that can be used as an easy pass/fail tester. Take a known good pressure regulator, attach it to the outlet hose on the PRIMED pump and start the pump. If it's an OK pump, the system will pressurize to an adequate pressure, and the pressure regulator will begin bleeding the excess gas. Make sure the pressure regulator dumps to a catch container.
Be darned careful with whatever you decide to do and do it in an open area away from the house. Gas and sparks are a dangerous mix.
That being said, I'm still amazed that the electrically charged rotors of the Bosch inline pumps actually spin in the gasoline....
Look at the pump.
Bosch and all of the others I've seen others have the terminals marked.
Don't run a pump dry, the pump needs gas as a lubricant to prevent damage to the bearings and to the pump rollers and roller contact surfaces.
In the car, gravity primes the pump which is why it's easy to put a pump on a car and fill it with gas before starting it.
On the bench, it's tricky to ensure gas is in the pump before you start. Maybe a hose with a siphon squeezbulb between the gas container and the pump to fill the pump before you start. Squeeze the bulb to fill the pump, start it up. Be sure to have a second container to catch the gas as it dumps out of the primed pump. This also cleans spiders and crap out of the pump.
In our systems, it's the pressure regulator valve downstream from the injectors that can be used as an easy pass/fail tester. Take a known good pressure regulator, attach it to the outlet hose on the PRIMED pump and start the pump. If it's an OK pump, the system will pressurize to an adequate pressure, and the pressure regulator will begin bleeding the excess gas. Make sure the pressure regulator dumps to a catch container.
Be darned careful with whatever you decide to do and do it in an open area away from the house. Gas and sparks are a dangerous mix.
That being said, I'm still amazed that the electrically charged rotors of the Bosch inline pumps actually spin in the gasoline....
QUOTE(rigglet @ May 21 2009, 08:54 AM) 
Awesome! Thanks for the quick reply. So there is no "positive" or "negative" terminal on the pump?
Yes, there is polarity to the power plug as mentioned above. There is a pix in Haynes that ID's the polarity of the plug.
QUOTE(kwales @ May 21 2009, 09:53 AM)
... I'm still amazed that the electrically charged rotors of the Bosch inline pumps actually spin in the gasoline....
No oxygen ... no fire
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