Blown 20A MPI Fuse = ECU?

1QUICK4 · 04-14-2008

Will a bad ecu cause the 20amp MPI fusable link to blow? Anyone had this problem? The Ignition switch/illumination 30Amp was blown as well.
I drove my car to work and it was fine, I tried to start it to go to lunch and it is dead.

I replaced the 30A and it is fine until I turn the key but the 20A MPI link blows immediately even with the key out of the ignition.

Possible bad Ignition switch? Maybe Internal short in ECU? anyone?

1QUICK4 · 04-15-2008

Nobody? Well fuck, hopefully it's something simple.

Looks like I get to do some fun electrical diag. when I get back from Chicago on Saturday.

gofastman · 04-16-2008

a blown mpi fuse makes me think shorted injector / harness, never looked at a wiring diagram for that circut though, check the injectors impedance with an ohm meter

1QUICK4 · 04-17-2008

The more I think about it the more I'm leaning towards the fuel pump circut or the MPI relay. I fucking hate not having access to wiring diagrams.

1QUICK4 · 04-19-2008

It's fixed!

The MPI relay had vibrated 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.

Thank god for the Mitsu graveyards full of spare parts in my garages