Hello, can and will anyone help a little? I've been through the service manual and the Haynes book so much I'm starting to dream, maybe have nightmares, about this car.

I installed a new fuel pump and two pump relays, pump came on for a few "test runs" in the 40 foot driveway, now the pump works very intermittently....like one in a hundred starts.
If I tap the starter, I don't hear the pump running, just one loud click (like a relay). each time I tap the starter the fuel line spits out a little fuel, but not enough to run my lawn mower.

Today I removed the fuel pump, made certain the connections were tight and the thing worked for about five attempts, now nothing but the "clunk" coming from the fuel pump area. The pump relay has the appropriate continuity,

Is it possible I have a bad pump that works only when it want to?

Any members around Columbus, OH who would let me look at their non turbo vacuum lines?

Thanks in advance for any constructive suggestions.
My wife wants her garage back.

 

Have you verified that power is getting to the pump?
Checked fusible link?
Is the ecu getting power?

 

Thank you NismoPick. Last night I ran 12 volts directly to the fuel pump and it came on. Tomorrow I will look closer at the other items you mentioned. My plugs were wet, so I might have a bad or dying coil too. I know, why were they wet when the fuel pump doesn't work? It will kick on every once in awhile. I printed the pages from the FSM and will start a new round of tests tomorrow. I really appreciate your response because I was starting to out on that proverbial limb.
I will post findings once I get them and if you have any other ideas, please send them.
Almost sorry I bought this car.....but not quite yet.

 

When trying to start without success you can easily inject enough unburned fuel to effectively flood the engine (using old carburetor terminology). this then prevents you from starting the engine normally. If you have checked everything and still no luck try this. disconnect a wire from the fuel pump so it won't pump (on a z31 pull the fuse). you need a fully charged good battery for this. hold the gas pedal to the floor and give it a long crank. you may or may not get a few pops. Do it again. it may run for a few seconds. do it again. When you no longer get any action reactivate the fuel pump and try a normal start.

 

Thank you Rogerz. I will try that in the morning. I sincerely appreciate every suggestion because like most cars, these have their own quirks that seem to be problematic in 280zx's. Again, it has been 30 years since I last owned one of these and I have forgotten everything I knew about 280z & ZX's cars.

 

I see that his is a fairly old post. Wondering if you were able to resolve your fuel pump problems, We were having a similar problem.. Replacement of ignition switch resolved our problem.