starting trouble - no power getting to fuel pump

SON240sx Automotive
1

I have a 1990 hatchback with a KA24E. My starting troubles began with the car just not starting sometimes.

I found that wiggling the wires in the trunk (which go to the fuel pump) sometimes got it started. Sometimes I had to wiggle the wires a lot, so I decided it could be old wires, or the plastic connector in the trunk. I cut out the plastic connector and hardwired it. It started right away, and ran fine for a couple days.

Now, no luck, no matter how much I wiggle the wires. I tried wire brushing where the wires connect to on the top of the fuel sending unit, and running new wires from the side of the trunk to the connections. Still no luck.

Then I tested to see if power got to the pump. The wires for the fuel guage have power, but the ones for the pump motor itself do not get power.

Power is getting to the fuel pump relay under the hood.

I have tried taking out the fuel pump and applying power directly; it works. It does seem to be the original pump, so maybe it works inconsistently… but that wouldn’t explain why power is not even getting there.

Does anyone have any suggestions?
(PS - I did try searching first)

2

When you tested the fuel pump wires was the relay still in place?
Make sure the wire isn’t broken… take out the relay and use a multimeter or sometihng else to make sure you get contact on both ends…
If the wire isn’t broken then it’s probably the relay itself.

Also have you installed a stereo or anything weird lately? 240s HATE bad grounds… spd-dmn’s fuel pump wouldn’t start once and it was just one poorly connect ground…
(It also did weird stuff like light up his clock but not display the time etc…)