Clicking from fuel pump relay 91 gsx

[haywooddsm]

Fuel pump relay on my 91 gsx was clicking, so I bought and installed a new one and the clicking continues. Anybody have any ideas on what it could be?

 

[gsx_eclipse99]

When does it click, like when you're driving?

 

[haywooddsm]

After the initial start up while idling, the idle jumps sparatically, if I give it has while it's clicking it just turns off, after a while it does stop though.

 

[steve]

Several things could be going on, have you checked the system voltage while this is happening? Low voltage can cause the relays to chatter.

The wiring from the ECU to the MPI relay and be loose or damaged. One side of the coil in the relay has power when the ignition is on and the ECU grounds the other side to active the relay. If the connection isn't solid the relay can switch on and off.

The relay could be bad. I've never seen this happen but it's possible.

The most common case I've seen is the ECU is bad and is resetting or the output for the fuel pump is damaged from leaking capacitors.