No power to electronic fuel pump

[tfsbecause]

I have a 1978 280z couple. It's been sitting for about a year, and driven very little for the last 4 years.

We switched out the electronic fuel pump with a remanufactured one from BAP. Problem is I am not getting any power to it.

I am not sure where to start...I'd appreciate any input, pics and whatever anyone has to offer. Thanks!!

~Liz

[70 Cam Guy]

I would start by checking all my battery condition/connections, fusible links, relays, and verifying my connections and grounds if they're accessible. You put the reman pump in, has it ever worked or is the new unit inop? You're certain it's pump? (ie no fuel pressure, you can't hear the pump running)

According to the wiring diagrams, when you key on, you should see 12 volts to the EFI Main Relay and Fuel Pump Control Relay. The control relay gets input signal from the alternator and/or oil pressure switch after the engine is running. It looks like the Control Relay actuates the Fuel Pump Relay. Diagnosis will be much easier if you have a test light or multimeter. The ignition relay should also click when you key to what looks like 'on' or acc. If I follow the decision tree, simply keying 'on' with the engine off will not run the pump like many newer cars.

Here's the service manual

http://xenons30.com/reference.html

You'll find fuel pump troubleshooting and diag on EF-35. The png I attached is from page EF-16

Without a test light or meter you can put your fingers on each relay when you key to start to feel if they are actuating.

I hope this helps, I know electrical can be a little intimidating at first. start with just double checking your connections when you replaced the pump. The connectors should be secure and there should be no corrosion. If the connections are good, check your fusible links, relays and ignition switch. You can take the battery out of the equation by connecting a battery charger, another battery or booster pack if starter cranking is weak. I am assuming this is a crank-no start condition

Edited May 30, 2009 by 70 Cam Guy

[sblake01]

These scans might be helpful also:

[tfsbecause]

when we ran a wire straight to the fuel pump we could hear it.

I've never done electrical testing. I watched it being done a couple years ago for an AC but that's about it. So I am not sure how to do the continuity test. I have a multimeter I can use and the FSM.

[70 Cam Guy]

You've got a good start, you know the pump runs and the battery ok.

Remember electricity follows a path from positive to negative. When the path is broken, the circuit is open and electricity will not flow. Probing for voltage 'backwards' won't harm the meter or do anything bad... it just reads a negative voltage. Check voltage by checking the terminal to ground, not across the relay. In other words, place the red probe on the terminal and the black probe to ground (negative battery terminal or suitable engine/body ground)

Continuity is continuous or connected from point A to point B. If it has continuity, the meter will usually beep. Using sblake01's middle scan, placing one probe on pin 91 and the other probe on pin 95 should produce a beep from the meter, or 0 ohms resistance.

btw, those are great scans from sblake, I'd check all three of those. Good luck!

Edited May 31, 2009 by 70 Cam Guy
proof reading is good!