EFI Fuse

So i have read quite a few threads on this but I still need help. I have a 1998 Tacoma 3.4L limited and i have had this fuse blow before and it turned out to be the fuel pump. Now I've tried the fuel pump already and its not the issue. I won't be able to work on my truck again until Sunday so I'm trying to get some info or help on the issue while i wait. So, this time it blew I was driving to work and gave it gas from a stop and it died on me. When i got it home it would blow the fuse every time I turned the key even without trying to start it. I checked the EFI relay as well and the relay is good and I can't find the Circuit opening relay anywhere but I can hear it pull in the contacts when its energized so I'm sure its working. Then I removed the O2 sensors and checked the wiring by the O2 sensors and still no luck. Yesterday i was able to start it after disconnecting the MAF sensor and then it died but the fuse didn't blow so i reconnected the MAF sensor and it started again. I drove it down the street and as soon as i stepped on the gas it died again and blew the EFI fuse. So now it starts, but as soon as I floor it or get the RPM's up it blows the EFI fuse. I just don't see how my MAF sensor would be the issue when the fuse blows from a full throttle but then again I am absolutely not a car mechanic. Also, I just replaced the alternator in it a couple weeks ago. Any suggestions? Thanks!

 

Circuit opening relay is very obvious, you’ll know it when you see it. It’s green and under the steering column.


Sounds to me like you have a short somewhere which is why you’re blowing through fuses.

@mechanicjon??

 

That’s what I thought too but I still can’t find it. There is nothing green underneath the steering column. I can hear it pull in when I put the efi fuse in but I can’t find it. There must be a short somewhere but I can’t find it or narrow it down.

 

You have to take the dash cover off.

Trust me it’s there. We have the same year truck.

Ignore the label, I made a killswitch for anti theft.

 

Awesome! That explains why I couldnt find it. Thanks for that, ill look for it today and that should give me one more thing to troubleshoot and should help me narrow it down some more.

 

Alright so I pulled out the relay and the fuse still blows when I turn the key. Think it’s just a short somewhere in the wiring?

 

Has to be a short somewhere.

 

Alright, so there is definitely a wire short somewhere. I unplugged the EFI relay and left the fuse out. Pulled the connector from the IAC valve and put one lead from my meter on the white/red wire prong and then the other lead to ground. Direct short somewhere because I'm only reading 1 ohm. It's almost impossible to look inside of some of these old wire looms. Any ideas or hotspots someone might know of with past experience? Thanks for help.

 

Check connector BN1 under the driver's seat, and where it exits the cab under the truck. Could be your fuel pump wire too.

 

Alright, i will have to check that tomorrow after work. Ill let you know what i find.

 

I did check the connector under the seat and found an issue I fixed but that didn’t solve my problem. I left my meter plugged in and started pushing and pulling on everything I could get my hands on and finally got it to read resistance. Looks like my issue is somewhere in this cluster of wires or that plastic thing that says 84 on it. Not sure what that is though. Didn’t have enough time to dig into it