This is for my 2006 Tribute 4 cyl AWD. A few months ago it started dying. Very intermittent but then becoming more regular. Diagnosed it to be the fuel pump. So I replaced that and the fuel filter and all was good until last night. Daughter came in and said it died 6 times on her way home. Would restart every time so she limped it home. Flipped the back seat and pulled off the top cover to the fuel pump so i can hear it. When key is on but engine not running sometimes the pump seems to surge and doesn't shut off. Sometimes it is quiet. when i do crank it it always starts and runs. BUT there is also a loud buzz from the engine compartment up near the front near under the battery. It is hard to pinpoint but very noticeable. Had the fuses exposed as i was checking with the fuel pump issue so i began to play. Every fuse that has to do with the PCM...when pulled shuts the sound off in the engine compartment. When I pull the PCM relay the sound stops as well. The sound is not coming from the PCM.

So I'm wondering if the fuel issue is tied to the buzz and it is an electrical issue. There is a youtube video with the exact sound but sadly no responses to it.

Anyone experience this?

 

It sounds like fuel relay, can you find it and touch it with finger to see it vibrates? It is normally located at the engine compartment inside the fuse box.

 

I have checked the relay. It seems to be working properly. It tests as it should.

 

Def sounds like the Fuel Relay, when cranking the pump is driven 100% but when running it is pulsed by the Fuel pressure sensor.

 

When I switched relays it still didn't work. And now the fuel pump has stopped working all together. Can't get voltage back to it. No obvious damage to wires leading from the pump back up to the firewall. What I need is a wiring diagram for this vehicle. I have searched the site but nothing comes up. Are there wiring diagrams on this site? Cheers!

 

Then I'd suspect the fuel pressure sensor, sorry can't help with a wiring diagram at the moment.

 

Got they haynes manual on-line. I'll see what that has. Thanks!!

 

Ah - I have Haynes on paper so won't give you any more info, let us know how you get on.

Remember that on most cars the fuel pump is deliberately de-energised after a few seconds if the engine is not running with the ignition on. This is to prevent a fuel leak on the pressure side being fed by the pump in the event of an accident etc. So if you just turn the ignition on but don't start the engine the fuel pump will be de-energised after a few seconds so that can give you false testing results.

 

Yes....I am aware. this was the convo in the garage that day..."Key on....key off....key on....key off....." HA