VP series 2 fuel pump not priming

[Splasho]

Hi guys. I've got a VP series 2; motor, gearbox and wiring loom in a hiace van. The engine was running but now the fuel pump doesn't prime when ignition is turned on, but it does operate after the starter is cranked for a few seconds. (But doesnt start).There is spark, but I don't know how to check the injector voltage. I know that the fuel pump runs parallel with the oil pump but I don't know what I should do. I found these circuit diagrams somewhere on the net. Are they correct. I have a multimeter but don't know where to start. Any help is greatly appreciated.Cheers

 

[Brett_jjj]

The oil pressure switch only powers up the fuel pump "as a backup" in certain circumstances such as when an ECU fails. (The ECU normally powers up the fuel pump), and the oil pressure switch will only supply power to the fuel pump once the oil pressure is high enough to turn off the oil pressure light . Check the fuel pump relay, swap it with another one. If the fuel pump is running after a few seconds of cranking, then I doubt the fuel pump is the reason why its not starting as it should start once the fuel pump kicks in, although it will probably take a fair amount of cranking over to get the oil pressure up enough to get the fuel pump running, and then the fuel pump has to prime and pressurise the fuel lines and rail etc before it will even attempt to start..

 

[Splasho]

Thanks Brett_jjj.I'll check that, but the fuel pump is working after cranking. Do you know what voltage I should expect to see at the 2 terminals at each injector?

 

[Brett_jjj]

Injectors get fed 12 volts from the EFI/engine relay. The ECU earths the injectors to fire them...

 

[Splasho]

Ive checked the output of relay.. >12v. Ive checked the output at each of the terminals on one injector.. there is >12v at each. Could the ECU be faulty and how would I test that? Thanks

 

[Brett_jjj]

Easiest way to test for a faulty ECU is to try a different " known working" one to see if the problem then goes away. Or try your ECU in a different vehicle to see if it suffers the same problem yours has..

 

[Splasho]

makes sense

 

[Splasho]

I bought another ecu from another wrecker. It is supposed to be a good one but I had no way to check it. I plugged it in and the problem is still exactly the same as before. What's next? Anybody?

 

[davemoni]

I bought another ecu from another wrecker. It is supposed to be a good one but I had no way to check it. I plugged it in and the problem is still exactly the same as before. What's next? Anybody?

Have you sorted out problem? You could try powering up fuel pump with another power source. see if engine runs. will indicate if fault is with fuel pump or not, check fuel pressure. To check injector pulses easiest way is with a noid light (led light available from most auto shops not expensive). Plug it into injector plug and crank engine, should flash if injector pulses are o.k. Just reread previous posts. Should not have 12 v on both pins of the injector, as was previously stated in earlier post 12v positive on one side and the other pin is earthed by the engine controller. Check wiring from earth side of all injectors back to ecm for correct position in ecm plug and no shorts to positve wiring.