EFI fuel pump not getting power.

[rustbucket]

My Bronco has been sitting for a few months while I've been working on the house and yard. I had a bad battery in it that I just replaced. I went out to start it for the first time, and I can't hear the fuel pump whirring. I can hear the solenoid clicking, but don't seem to get power to the pump. I checked the voltage at the pump and there was none. Is there a way to test the solenoid? Any other likely culprits?

 

[904Bronco]

My Bronco has been sitting for a few months while I've been working on the house and yard. I had a bad battery in it that I just replaced. I went out to start it for the first time, and I can't hear the fuel pump whirring. I can hear the solenoid clicking, but don't seem to get power to the pump. I checked the voltage at the pump and there was none. Is there a way to test the solenoid? Any other likely culprits?

I am assuming that your rig ran before it sat... But either way... "Clicking" Do you mean the Fuel Pump relay? Does it have power to it? Not just the power to close it from the computer. Does it have power on the fuel pump side when the ign switch is in the start position? Check the fuel pump ground and other wiring. Did some critter make a meal of it? Do you have an inertia (sp?) switch installed? Has it been tripped? Push the Button on top and reset it. Depending on what you find, you could go in other directions...

 

[SaddleUp]

Check the output voltage at the fuel pump relay. I have mine mounted in a location that gets it wet (which I need to change around one of these days). Twice now I have had to replace the relay because it went bad. The first time it was engaging on it's own with the ignition off. (2 mornings in a row I went out and the pump was running without a key in it) The second time it had voltage coming off it with the ignition on but it was low. As soon as I tried to start it the voltage dropped to zero. Replacing the relay fixed it both times. Also don't forget to check the inertia switch if you have one installed since it is usually placed inline between the relay and the pump and would cause the same thing.

 

[rustbucket]

I'm a little baffled. I checked that I do have power to the relay. One of the terminals is constant hot, while another is hot on ignition. I replaced the fuel pump relay, thinking that might be the problem, but still no go. It looks like I'll need to do some further investigation. I get a code 85 and a code 96 in the KOEO test. I don't think code 85 has anything to do with it, as it is a canister purge circuit failure or a transaxle failure. The code 96, however, is a fuel control circuit failure. I do not have an inertia switch. Could the computer be bad?

 

[SaddleUp]

When the fuel pump is on 3 of the relay terminals should be hot. Basically all of them except the ground. I doubt it's a bad computer. Sounds like the problemis between the realy and the pump. Note: If only 2 wires are hot at the relay then there is a problem there.

 

[surfer-b]

when you turn the ign. on(KOEO position) does the relay click on for a few seconds then turn off, it should to prime the system maybe 4-5 seconds i don't recall the exact amount of time, the relay will disengage with no engine rotation, when you turn the ign. to start position the dist. sends a signal to he computer that engine rotation has started and to turn the relay on. So what im getting at is you might want to have someone turn the engine over while you check the load side of the relay ( the wire feading the fuel pump).

 

[SACHEM]

My bronco has had the same "will crank but won't run the fuel pump" issue. I checked the relays and found them to be full of water and extremely corroded. Anyway I went to the junkyard and found another set and now it's running strong again. I just have to figure out how to get them out of the elements.

Have you taken the relays out of thier cover to see what they look like?

 

[rustbucket]

I took the relay out, and it was pretty caked up inside with mud. I replaced it thinking that would solve the problem. Still no go. Then I realized, with the help of another poster, that switching the ignition on and crawling underneith the Bronco to test the voltage at the pump wouldn't work, as the pump is only energized for a few seconds after the key is turned. I had a buddy swing by to turn the switch while I was under there with a multimeter. The pump is getting power after all. A new one is on its way. Thanks to everybody for their help.