1977 280z fuel pump problem

[omar_munoz123]

I recently bought my 280z a few days ago the car drives fine and everything but i noticed that the fuel pump is still on while the car is on ACC, i know for a fact this isn't right and was confused at why it was doing so.

I looked under the car and found that fuel pump had been replaced at some point in it's life time and i retraced the wires and they end at the bottom of the passengers seat, they're connected to some sort of relay.

i need help! i don't understand why the fuel pump is still on while the engine hasn't even started i'm scared it could flood the engine. I hate to take it to a mechanic to fix it for me and i figured i could do it myself.

PLEASE REPLY!!! your help would be very much appreciated!

[Wade Nelson]

Whoever wired it up hooked it to an ACC circuit instead of an IGN circuit.

My guess? they did that on purpose to try and reduce vapor locking problems. On a hot day, they climb in the car, switch it to ACC for 5 seconds to prime the fuel rail, and THEN crank the engine.

You could certainly switch it back in about 5 minutes, just re-wire the relay to an IGN circuit instead!

But how often do you sit in the car listening to the radio on ACC, or whatever? Unless you have a leaking injector, you shouldn't flood the engine.

Or go a step further, and add a momentary switch so you CAN prime the fuel rail when you climb in, but connect the circuit to an IGN feed.

I've actually thought about doing that to MY car to see if I can reduce the hot-restart problem these cars have.

[omar_munoz123]

hey thanks for replying! where exactly is the IGN circuit? thank god this sounds easy! haha

[Wade Nelson]

Honestly, Omar, if you don't know how to find an IGNITION feed wire you can tap into to run the relay, you need to find someone who does to help you.

On the back of the IGNITION switch itself there are is an input for the battery and outputs for ACCESSORY and IGNITION and CRANK, but you probably don't want to cut into those wires, but instead find something under the hood or the dash, like the feed to the coil or something else that ONLY gets powered up when IGNITION is on. And it has to be a circuit that you're not going to screw up by tapping into it.