EFI fuse blown

So I have a 96 2.7L 4cyl that keeps blowing the EFI fuse. I've read a lot to check the O2 sensor wires for a short, but they looked fine, so I went ahead and replaced the fuel pump. It started and ran fine after I did that, but I went to drive to work this morning and the same thing happened: the truck died and the EFI fuse was blown again. I checked the EFI relay, it was fine, and I replaced the fuse again and it started right up. I let it run, jiggled some wires around to see if I could make it short again, and nothing happened, it ran fine. What's the best way to find out where the short is occurring?

 

I'd start by looking as closely as possible for suspect areas along the wiring harness under the hood first. I think that's really all you can do while it's running.

 

Giving me flashbacks from my 87 4runner.

For me, I had a wire that was shorting by the transmission. What a nightmare.

I contacted some 12v electrician off of craigslist and paid him $75/hr to find it. Took him 3 hours.

 

On my '99 3RZ, the EFI fuse has one wire going to the ECM, and one wire going to a primary terminal of the EFI relay. Of course, the other primary relay terminal has a wire going to the ECM.

What I would do, is completely rule out the EFI relay (even though it was 'checked'). Assuming your fuse/relay box is similar to mine, the EFI relay is small and black, and interchangeable with the nearby 'tail-light' and 'power-outlet' relays.

Swap the power-outlet relay with the EFI relay, and see if that solves the problem. If it doesn't, then it could be a bad ECM

 

I swapped out the EFI relay with the tail light relay and it worked fine, so I swapped them back to make sure, and it still worked fine. In fact, I just drove around the block a couple times and it hasn't blown a fuse since I tried to drive to work the other morning.

 

Old thread revival but this got me off the side the road this morning. Truck suddenly died and refused to start on my way to work. The o2 sensor plug in ended up falling onto the exhaust and melting itself on.prayed it off, taped the shit out of it,swapped the fuse and away she went. Also seems to have gotten rid of my cel code.... for now