Im officially stumped. Any electrical wizards out there?? Alright so i started looking into what was going on here a bit more and realized i couldnt hear the fuel pump when i turned the key on. First i checked the fuel pump fuse and it was fine. Then i checked for power at the fuel pump connector and there was nothing. Then i checked for power at the fuel pump fuse (F2
and still nothing. Then i checked the ground circuit off the connector and all was good. So after this i thought the problem had to be the fuel pump relay. I went out and bought a new one today and plugged it in but unfortunately, not that easy.
I attached a copy of the wiring diagram i was going off, (hopefully it shows up)
and as you can see, along the way from the fuel pump relay to the fuel pump there are 3 other fuses and their associated components which get power from that relay. The other 3 are the fuel injectors (F32), and two others for engine management (F34) and (F43). With the new relay in place i checked for voltage while turning the key on at all 4 fuses mentioned, and i read the same at all of the fuses besides F32. At fuse 32 i read no voltage , about 0.004, and it didn't change at all with the turning of the key. At the other 3 however i read 1.8v and it would drop slightly while turning the key on. And finally at the fuel pump connector i read about 1.8v again, but when i turned the key on it would jump to 12.5v for a split second before dropping back down to 1.8.
I decided i would take a look at the injectors and see if everything looked alright, and i couldn't find any issues. No shorts to ground.
A couple things i find strange about all this is that while i was reading 1.8 volts at the 3 fuses and the connector, the key was out. Should there be any voltage at all without the relay making contact? Also i was only reading 12.5 volts for that split second at the connector, nowhere else. Another thing i find odd is that for the last week it was an intermittent problem so whatever it is it came and went.