Yesterday my car lost all fuel pressure. I am running a walbro 255 with the hotwire kit. Everyone who has this kit knows it pulls power straight off the alternator. Yesterday, my car lost all fuel pressure, and it turns out the pump wasnt getting any power b/c the wire that goes from the battery to the alternator was corroded and falling out of its connector. Anyway, after I got that fixed and fired her back up, the fuel level gauge is pegged past full and wont move. It does drop down when the car is off though. Anyone have any ideas? I know the floater in the tank could be caught, but I dont see how it could randomly get stuck after it has worked fine for the last 9 months.

Sounds like the level sensor circuit may be "open", causing the gauge to peg.

The fuel gage is only a variable resistor. It will show low at it's lowest resistance and full at it's highest resistance.

Since you've already had one corroded wire, it's probable that you have another wiring issue to the gage causing your problem. Ohm it from one end of the car to the other. C405 with the purple wire (connector behind the rear seat outside ahead of the differential) up to the instrument cluster.

Where is this sensor?

The fuel level sensor is in the fuel tank.





Its attached to the pump support bracket, and has a long rod with a float attached to it. The float "floats" on top of the fuel level, and the rod moves the variable resistor that Speedy is talking about. You check the resistance of the sensor as he outlined.