'90 4runner troubles

[YZFjeremy]

'90 4runner EFI fuse troubles-FIXED.. thanks

I have a 4cyl, 5pd, 4x4 4runner that has started to randomly pop my EFI fuse.

I have traced almost all of the wires in the truck.. tried a new relay, check for a short near the oxygen sensor.

I can just be driving down the road the the truck will die... and right then if I put a new fuse in it it iwll pop as soon as I try to turn it over. I have been towing it home and looking for problems, this was the 3rd time. I had left it parked in the garage for 2 days and not touched it.. I tried a new fuse and it started right up.

Does anyone have any suggestions what might be causing this. Thanks a bunch.

Jeremy

 

[captwalker87]

If you have had any work done yo your tranny, driveshafts or exhaust recently, chances are thats the blame. I know you said you looked for a short near your O2 sensor, but check again. There are 4 wires that go to your O2, and 2 of them are for the O2 sensor heater. If those two wires are grounding out anywhere, itll blow your fuse. Your O2 sensor wires should run from the O2 -> above tranny -> in tranny harness -> passenger side engine compartment -> engine wiring harness -> ECU. check as much as you can.

 

[YZFjeremy]

yeah I had that part of the harnedd pulled back through the engine compartment and inspected in thourghly... turns out the taped wires going to the diagnostic plug, located on the on the fuse box in the engine compartment, had worn through the tape and right though a wire...
Got it all fixed up and its running great now... thanks for the response...