Electric Fuel Pump Not Shutting Off

[porkchop]

I have a 24 volt Faucet pump and it has worked great for the last 4 years. Friday, however, I changed the filter closes to the carb and now the pump will not shut off. It just continues to push fuel to the carb. It use to shut off when the lines were pressurized. It is a self priming pump so not sure what can be causing this. Air in the pump? Thanks.

[gimpyrobb]

Mine is the same way. Have you made sure there isn't a seal leaking fuel onto the motor? I have seen filters near the carb leak fuel.

[porkchop]

I thought the same thing at first, so I plugged the line completely before the filter to see if it would shut off. Nope, still kept running. Tonight I am going to pull the pump off and see if maybe something is stuck in there allowing air toget in.

[Barrman]

What kind of pressure are you getting out of it? If you are still getting 3-5 psi and a good bit of flow, then it is working ok.

Actually, if your pump was shutting off when it got to a specific pressure before, that could be part of your going down the road problems. By the time the float went down enough to drop the pressure, the pump was playing catch up and might not have been able to get enough fuel to the carb if you were in the throttle pretty hard.

My pump runs all the time with or without pressure. I don't remember the brand though.

[randyscycle]

All of the inline type electric fuel pumps I have seen run constantly, unless they are on a relay like a fuel injected system. They usually have an internal check valve that allows some of the pressure to bleed back once the needle valve in the carburetor stops the flow of fuel.

[porkchop]

From the day I installed it the pump would shut off when the line was pressurized. It would only run when the truck was running and suppling fuel to the carb. I haven't measured the pressure yet, but plan to this evening if I can get the tool I need. I have a couple of regulators that I can install if I need.

The other part of this mystery is that the pump continues to push fuel into the carb and the needle valve can't stop it. The needle valve has been checked many times and it moves freely and isn't sticking. I removed the adjuster screw out the top with the pump running and fuel just came shooting out of the hole and the vent tube.

This is the pump I have:
http://saturnsurplus.com/miscpage/24fuelpump.htm

[amphi]

The link below shows "positive shut-off" = NO -- for the 480517E

http://www.facet-purolator.com/index...d=14&Itemid=36

Some do have positive shut-off

Check the model number on the pump with the specs in the link.

[porkchop]

Thanks! I will check the numbers tonight because the one on the Saturn site says it doesn't, but I am positive it does.

[Barrman]

I have the same pump sitting in the glove box of my M35 gasser as a back up in case the mechanical pump dies far from home. I plugged it in and it made noise, so I figured it was good. I have not pressure tested it however so I don't know if stops clunking away when under pressure or not.

I would guess however that your needle and seat are worn out enough that they can't hold pressure anymore. So, your pump never gets enough pressure built up to stop audibly clicking. The filter might have had enough gunk in it to reduce the flow enough that pressure in the line before it was high enough to stop the pump.

I would not recommend any of those Mr. Gasket type regulators. They might work for a year, a month a day or an hour. You never know when they will fail. They do fail specatularly however.

I have an electric pump because I have 2 a/c compressors on my engine. I forgot why you are running electric instead of a manual pump.

[porkchop]

I plugged the line and the pump still runs, so there is a bleed off somewhere. I have a holley regulator that I am thinking of putting on.

I am running an electric because of the 292. I had to make new mounts and they cover up the spot where the manual pump goes. The mounting is offset on a 292.