Why is it my cars never seem to have simple problems?

Car is a 1994 TS Magna V6 auto. Car died on me on my way home from work one morning. My initial diagnosis was a fuel issue, given the way it died, and upon further testing found I wasn't getting any fuel to the fuel rail. The fuel pump relay was clicking away so I assumed it was the pump itself. I fitted another pump but still no fuel so I changed the relay just in case but still no joy.

I tested the voltage at the connector at the fuel pump and found I'm not getting any power to the wires that go to the pump only power to the sender unit (mine is the one with the sender and pump in one unit). I then connected power to the relay bypass connector in the engine bay and the car fired into life.

Is there somewhere on these cars that could pose a possible issue regarding power from the relay to the pump. I should also mention that I have checked the connector inside the boot (it's a sedan) and I'm getting the same readings there as at the pump connector.

I'm sitting here studying the wiring diagrams but they're not helping much at this point in time. This is causing me a few more grey hairs (something I could do without) and plenty of head scratching.

Sorry also forgot to mention I do not have any kind of alarm or immobiliser fitted.

Don't know why it is saying that was my first post, I've posted on here before, just not for quite a while.

There is usually some kind of timing circuit to keep the relay powered on and that timer is continously triggered as long as the engine is running.
Not looked at how this is done on the TS but maybe that is a good place to look for problems.

I would first check the integrity of the wiring between relay and pump (just in case its broken).

Update: I towed the car home when it broke down and couldn't get it up my steep driveway on the car float so had it out the front on the side of the road. I decided to connect the battery to the relay bypass and drive the car into the driveway to make it easier to work on. Once I got the car in I disconnected the wire and the car kept running. I switched it off, restarted it and it ran. Hasn't cut out since.

Given Aquars response this is what I am thinking may have been the issue, let me know if this sounds feasible. Initial issue was either a faulty pump or relay, both of which have been changed, but after fixing this issue I wasn't getting power to the pump due to the "timing circuit" Aquar mentioned as the car wasn't running. Once I connected the pump directly to the battery it pressurised the system (and eventually cleared any air in the lines) allowing the car to start and allowing the "timing circuit" to be completed powering the pump through the usual circuit.

I've been a bit concerned that there may have been an intermittent wiring issue that could come back but if the above is correct it should be all beer and skittles from here.

Wiring diagrams look like the fuel pump relay requires a two stage process to energise - Drive needs to be in N or P, and then the ECU will switch it on and keep it sealed on after the drive is moved out of N or P. The ECU holds the relay in once started.

Still could be a wiring prob (only an issue if vibrations from driving just enough to break a bad connection perhaps).

As the ECU has control of the relay it could also be an ECU intermittent fault too.

Thanks for the responses guys. Car is now running like a dream. Since my last post the car ran every time I started it but took some time to start especially from cold. Once it was running it would die down in revs if you used too much throttle. I put a new fuel filter on and also decided to chuck on a new set of plugs and leads, a new air filter and check the dizzy and rotor button (last 2 items aren't that old just gave them a clean up). Now that it's had a quick tune up the car starts easier than ever and is purring like a kitten.