Working on a 90 runner 3vz. Blew the efi fuse, so I checked the 02,maf,ecm, and they are all good.
When this first happened I was driving when the low fuel light came on, but the tank was full. Not long after that the fuse blew and after that the guage reads properly with just the key on , but when I start the rig it grounds out and goes to E.
I haven't pulled the tank yet, but I was wondering if there was any relation between the sending unit and the efi fuse, cause I would not think so?

 

Off the top of my head, the sending unit doesn't use the EFI fuse.
Double check the wiring diagrams to make sure.

To check for a short you can jump a light bulb instead of your fuse. This will allow the circuit to stay active so you can check it.

 

yeah you're right it doesn't, but I was thinking maybe the fuel pump circuit and the sending unit cercuit could be rubbing on each other. Guess I won't know until I pull the tank.

 

Just disconnect the connector and see if it still blows the fuse. If it does it's not in your tank.
If not, it's probably in the tank.

 

My guess is that you've got an o2 sensor shorting out.

 

The sensor itself?, cause I followed wires and they look good.

 

All the wires? Both O2 sensors?

 

"Both"? There is only one that I know of?

 

It depends on what type of vehicle emissions you have. For example a california pickup has two O2 sensors. One before the cat, and one after the cat.

 

This model has one just before the cat.