No power to fuel pump. Wiring? Help!

[caustad]

I recently replace my tranny and transfer case but had the car garaged for about a year before I did the work. After I finished it would not start and the fuel pump wasn't getting power. I checked all the fuses and even swapped out the ecu to try another just in case... Still no power. I decided to do a fuel pump rewire and the fuel pump turned on, but the injectors just sprayed wide open and wouldn't shut off. It's not the ECU because it does the same thing with both. I also thought that I might have pinched a wire when I put the tranny back in but I didn't see anything. Any ideas?

[Kracka]

Maybe a mouse or rat made a home out of your wiring harness.

[520Talon]

CAS. I had the same problem and it was the Crank angle sensor. It just went after I shut the car off one day.

[Goat Blower]

With the ignition on but without the car running, take off your CAS but leave it plugged in. Turn it by hand, you should hear the pump come on for a few seconds. If not, the CAS is bad. If it does, check your MPI relay.

[caustad]

I'll try the CAS thing. I think the MPI relay is good because it clicks when I turn on the ignition. Thanks

[FORSFED]

Just out of curiosity, how does the CAS come into play with the fuel pump turning on? I've got the same issue with my car. After storing it for a year, the pump wouldn't turn on any more so I hardwired it.

[Sean485]

The ecu has control over the fuel pump relay, the ecu energizes the relay for a few seconds when the ecu first powers up to presurize the system and then it will keep the relay on as long as it is recieving a signal from the cas (ie it thinks the car is running). So by doing what Goat Blower suggested you are just telling the ecu the car is running when it really isn't so it should, assuming the cas is working correctly, keep the fuel pump turned on, pulse the injectors, and fire the coils without having to actually be cranking the engine ;)

Edit: Also, make sure you turn it clockwise since thats the way the engine rotates and i'm not sure how the ecu would handle the signals if they were running in the reverse direction...

[FORSFED]

The initial pressurization of the system has nothing to do with the cas though right since the car isn't running? I'm hearing the relay click on when I turn the ignition switch on, but the pump doesn't respond by turning on to pressurize the system as it should.

[Sean485]

The relay is 2 part, it is a relay that clicks on when the key is turned to "run" to tell the ecu to turn on and then after the ecu is on the ecu sends a signal to a differnt trigger wire on the relay and the fuel pump relay section of the relay will then send power to the fuel pump.

And no, the CAS has nothing to do with the initial priming of the fuel system but just because you hear a relay click it doesn't mean its the fuel pump relay. I dont have the pinout for the mpi/fuel pump relay handy but if you could find it you could test if the ecu is sending the signal to the relay to turn on the fuel pump while your turning the cas.

[FORSFED]

I'll have to look it up again. I know that the MPI relay does two things, one of which is turn on the fuel pump to pressurize the system upon key on and the other I don't quite remember. Probably something like you said with turning on the ecu.

Anyway, I don't get that initial prime of the pump nor do I get it to turn on while cranking. The hot wire at the pump shows nothing. From what I'm understanding, this would be an issue with the MPI relay, however I do hear it click...