Fuel pump relay making noise

[Sawbladz]

So this is confusing and not a problem I expected to have. Today for the first time in 6 months I put the battery in the car. As soon as the connections were made, the fuel pump relay starting making a loud noise like it was vibrating. What could cause this?

In the past 6 months everything in the car has changed including MAFT-Pro, engine, wiring harness. I just need a place to start to look for errors. The wiring harness and MAFT-Pro were hooked up and running on a different car before being put into my car so I don't think there should be too many issues with it but I can't say for sure.

The car isn't ready to be started I just wanted to see if it would turn over and make oil pressure. Basically I am just trying to start trouble shooting for errors I made but this one confuses me.

---------- Post added at 06:58 PM ---------- Previous post was at 06:51 PM ----------

It will likely be useful to know that I have not done the 12V mod though I do intend to. I have also not yet changed the fuel pump to the walbro. It is still on the stock pump.

 

[Dirgle]

What is the voltage on the battery?

 

[Sawbladz]

Just tried to go check but my multimeter is dead and I don't have any 9V batteries in the house. Were you thinking it might be cause by a low charge on the battery?

 

[Sawbladz]

Anybody else have any ideas? This is rather confusing. I was considering unplugging the relay since I don't want fuel anyways for turning it over. Still need to figure it out though.

---------- Post added at 10:49 PM ---------- Previous post was at 10:35 PM ----------

Just to trouble shoot further. I went out and unplugged the pump relay. Then hooked up the battery leads and check the dash. I have the check engine and battery lights on at all times. Whether the key is in or not.

However, the car turns over fine. So there is a slight bit of good news.

 

[dumbo]

Your going to need a meter for this.

You could unhook the relay and slap 12 volts to the coil and see if it still does it, if so get a new relay. If not, maybe a bad/loose conection somewhere, or like Dirgle said battery voltages is low.

 

[Sawbladz]

Will definitely be getting a new battery for the meter tomorrow but by the way the lights lit up and how well it turned over I doubt its battery voltage related. I also doubt this is the relays problem. It worked perfect before the car was taken apart and now it doesn't. That added with the lights on the dash point to a wiring problem but I don't know where to start the search.

 

[dumbo]

Well put 12 volts to the coil circuit of it, if it still chatters there you go.

 

[Van]

Sawbladz,
My Supra is having the same sumptoms; Fp relay chatter and dash lights: check engine, battery and Alt lights all light, without the key in the ignition. I only rebuilt my motor, nothing else was touched. Have you gotten it sorted out? Van

 

[Van]

PM sent

 

[Evilempire1.3JZ-GTE]

There is a capacitor in the circuit opening relay if it leaks or blows up just take the cover off it & replace that capacitor.

There is 2 coils in the relay one turn the fuel pump on only while cranking the car.
The other one is when the ECU turns on the fuel pump & keeps it on.