EFI Fuse intermittently blowing

[seanf]

I have a 1997 4 Runner, Automatic, 3.8 liter, automatic.

A couple of months ago the EFI fuse started blowing. I is starting to happen more frequently. I have read all of the threads about this problem. I checked over the wiring for the 02 sensor and the ground at the intake manifold. I also brought it to a mechinaic to have them look it over. They could not find anything but replaced the EFI relay. It did not help.

The symptoms seem to be, it only blows if the engine was already warm when it was started and blows with in a minute or so of starting. Unfortunately usually when I pull out in to traffic.

I have heard there is a heater in the O2 sensor. Is it possible that is shorting out?

Any other things that I should look for?

 

[seanf]

EFI Fuse

Still looking for any suggestions.

 

[koulee]

Alternator or battery perhaps? You might have to take it to the stealership.

 

[the great him]

i dont have much experience with the 3.8l, thats a fairly rare motor so im not sure very many of us will be of much help, but id start looking at grounds and look for lose connections

 

[seanf]

I had said 3.8 liter, I should have said 3.4 5VZ-FE.

sean

 

[the great him]

I had said 3.8 liter, I should have said 3.4 5VZ-FE.

sean

oh oh oh, the 3.4l well yeah we all are familiar with that motor lol -just givin you a hard time... but yeah check your grounds, it sounds like you have a short someplace and its blowing your fuse.

 

[BlackCat914]

i dont have much experience with the 3.8l, thats a fairly rare motor so im not sure very many of us will be of much help, but id start looking at grounds and look for lose connections

lol, and you called me a smart ass in another thread?

 

[the great him]

lol, and you called me a smart ass in another thread?

touche :fencing:

 

[the great him]

^^^ this forum is only big enough for one of us... lol

 

[BlackCat914]

^^^ this forum is only big enough for one of us... lol

ound::tea:

 

[BlackCat914]

^^^ this forum is only big enough for one of us... lol

I just went back and looked and it wasn't even you said that to me. ound:

 

[the great him]

I have a 1997 4 Runner, Automatic, 3.8 liter, automatic.

A couple of months ago the EFI fuse started blowing. I is starting to happen more frequently. I have read all of the threads about this problem. I checked over the wiring for the 02 sensor and the ground at the intake manifold. I also brought it to a mechinaic to have them look it over. They could not find anything but replaced the EFI relay. It did not help.

The symptoms seem to be, it only blows if the engine was already warm when it was started and blows with in a minute or so of starting. Unfortunately usually when I pull out in to traffic.

I have heard there is a heater in the O2 sensor. Is it possible that is shorting out?
i do not believe our trucks have a preheater in the o2's, i think that is something found in higher end cars.
Any other things that I should look for?

i answered you in red...

the other thing id look at is getting your injectors looked at, like the wire harness for the injectors, get them ohm checked -injectors and harness). also maybe the fuel pump as well, im not sure if it is on the same system as the EFI or not but id be it is, and you might have a faulty fuel pump thats starting to short out and kick the bucket. but again these are all just guesses sorry i cant be of any more help.

 

[brokenrunner]

i know this thread is old as hell....but im having the same issue. 01 3.4l. blows the fuse soon as you turn the key on. had an issue with the ignition switch wiring so i replaced all that along with the switch. replaced the ecu, o2 sensor wiring is all intact. fuel pump is good.. starter is good, pulled intake mani and inspected injector wiring. its all good. grounds are all solid and not corroded from what i can see. replaced the efi relay and circuit opening relay. still blows fuses. im on my 3rd box of 25...and its almost gone. ready to burn this thing to the ground.
not sure if im overlooking something small or what. any ideas?

 

[Bad Luck]

You have a short to ground on the power wire in the circuit that is on that fuse. You'll need a wiring diagram of that circuit, a voltage meter, and knowledge of how to diagnose circuits with it. Or take it to a mechanic. Good luck.

 

[jgue467]

right, find the culprit wire shorting (hot to ground) and either fix it or rewire that connection.

Short could be in engine compartment. Toyo likes to run electrical wires with high current right along metal that moves and vibrates until it wears through.

Mine shorts on the left front side of the engine, right near the oil intake. Several layers of thick electrical tape took care of that.

Luck and enjoy the runner. :cowboy:

 

[naturerunning]

OP has this issue been fixed? I would live to know what the culprit was.

 

[Crvernier]

Loose Inyector Connection

The issue with mine was a loose connection to one of the fuel injectors. The secure clip broke and and the false contact was causing the fuse to blow. Temporarily I secure it with a tie wrap, while I buy the connector harness.
Thank you all for your help!

 

[Devbot]

makin too much power!! :rockon: ound: