"MPI" Fuse blows with key off?
 

The MPI fuse in my GVR4 keeps blowing the instant it contacts the blades in the fuse box, even with the key off. I'll do a little more digging on it tomorrow and even bust out the service manual, but I'm hoping someone has run into this sorta thing before and can save me some troubleshooting BS.

Its blown the MPI fuse before, when I turned the key, but it has been as simple as replacing the fuse.

Car ran fine on sunday, but yesterday morning I went to start it and it just cranked, so found the fuse blown, and went to replace it, but it instantly pops, and I haven't even had time in daylight the past couple days to poke around under the hood.

any ideas?

Re: "MPI" Fuse blows with key off?
 

Check for wiring that has frayed. Its going to be time consuming, but I'd check the wires to the starter, alternator, O2 sensors and fuel pump first.

Re: "MPI" Fuse blows with key off?
 

I've had an MPI relay vibrate enough to somehow short itself out internally on its own metal casing. Looked good from the outside but when I took it apart you could see where it arched out.

Quick easy check

Re: "MPI" Fuse blows with key off?
 

^That's exactly what happened!

I checked for a short at the fuse, then went to pull the relay to see if the short went away, and noticed the cover was loose. Couple of zip ties and it's good as new.

Re: "MPI" Fuse blows with key off?
 

Glad I could help

You can take the cover off and put some electrical tape where it contacts if it ever happens again