01 silverado no power to fuel pump HELP!!

[cstm68]

My 01 silverado died while driving the other night and would not fire, I had it towed to my work and the next day it fired up just fine a few times then stopped. The fuel gauge has been acting up recently so I decided to replace the pump. Now it is still doing the same thing, when it doesn't start it is not getting any power to the pump. Any ideas why it only gets power sometimes?

[69chevytrucker]

check the relay

[cstm68]

I replaced the relay and the new pup came with the upgraded plug

[69chevytrucker]

mine did the same i had a loose wire above my left foot dont really now what wire but it was happening to me alot and i broke down while driving on the hiway reached under my dash above my left foot and just pushed up on the wires and hit the key and fired right up never had prob again so if you can figure what wire is above your left foot that has to do with fuel it might be it

[austinstocker]

Are you sure its not getting power to the pump or is it just not coming on?

[cstm68]

I tested the power wire at the pump and there is no power. The sending unit has 12v but the pump section doesn't, I leant do it all the time. Sometimes it has power and starts up just fine. I heard that the pump is wired through the oil pressure switch, is this true?

[austinstocker]

No, the fuel pump 12v circuit is not in line or affected by the oil pressure switch. Next time it does fail, check for power at the ECM B fuse under the hood. It is possible that there is a poor connection at the fuse box/ lack of 12v to the fuse. If there is still power going into that fuse, and obviously the fuse is still good because it is intermittent, then you would need to move on to checking the PCM signal to the control side if the fuel pump relay - assuming that the new relay is good.

If you understand the schematic that is printed on the side of the relay, you can jumper the side if the relay that sends power to the fuel pump. If all other circuits test ok in the system, and jumping the relay causes it to fire back up, you have narrowed it down to the relay itself or the PCM. Just let it be known that the PCM is one of the least likely causes of failure in my experience with GMs if that vintage.

There are a few relays near the fuel pump relay that are the same part number that can be swapped in case you are having any doubts about your new relay.

Make sure that all the grounds are good, clean and tight before getting too carried away.,,

Good luck, let us know how it goes.

[austinstocker]

What happened with this?