Faulty Gas Gauge

Sounds to me like an electrical problem - either the sender is bad or there's a wiring fault somewhere.

I can't think of any way the elbow mod itself could have caused this.

Could you have loosened or disconnected some wiring when doing the mod?

I did the mod with a guide from a thread from here. I doubt I messed up with anything because I triple checked every step before I executed them.

How about fog lights? I noticed everytime I turn on my fogs, the gas gauge goes down a bit. Is it possibly draining the battery causing the gas gauge to go whack? Also, when I leave it unattended with the lights on with the engine off, the gas gauge goes to empty. Possible cause? If so, what can I do to fix it?

First off - how are these fog lights wired up?

If they're powered directly off the battery rather than another circuit you need to specify where you're grounding them.

Is there any other electrical item that is affected by turning on the fog lights (e.g., dash lights dimming)?

I had the SAME problem on my 99 taco! i have a body lift on my truck and since the frame and the cab where not grounded to each other anymore it use my fog light ground and when i turned them on the fual gauge lost ground, i added a thick wire from the frame to the motor and it solved my problem... maybe this helps you :shrug:

Enola Gaia said:

First off - how are these fog lights wired up?

If they're powered directly off the battery rather than another circuit you need to specify where you're grounding them.

Is there any other electrical item that is affected by turning on the fog lights (e.g., dash lights dimming)?

Click to expand...

the fog lights are wired up the fuse box (positive) and the ground wires are hooked-up to the front metal bumper and hooked up to a small metal piece under the dash for the switch. as for other electric items that may be affected, i only have noticed the fuel gauge acting up.

COMAtized99 said:

I had the SAME problem on my 99 taco! i have a body lift on my truck and since the frame and the cab where not grounded to each other anymore it use my fog light ground and when i turned them on the fual gauge lost ground, i added a thick wire from the frame to the motor and it solved my problem... maybe this helps you :shrug:

Click to expand...

i'll give that a try.

UndefinedTaco said:

Mine does that

but only on 1/4 of a tank or below.


I'll drive it and it will drop to the E level almost after like 10 minutes of just cruising in town..
then if I stop and just sit somewhere while its running for like 5-10 minutes..it will rise back up to like 1/4 tank:lol:


I think it's just not reading it accurately since there is so little in the tank, and it's all sloshing around while driving..


Goodluck on the fix

Click to expand...

That's exactly what Mine does! But it does it no matter how much is in the tank :selfbonk:

havent checked up on this thread lately and unsuccessfully, i havent found a way to fix my problem. i was thinking of getting new fogs or rewire them somewhere else.

out of curiosity, i looked over the elbow mod guide again and noticed that it recommended that i remove the EFI fuse while doing it and install back after its done. possible cause? o_0

Project_13 said:

... out of curiosity, i looked over the elbow mod guide again and noticed that it recommended that i remove the EFI fuse while doing it and install back after its done. possible cause? o_0

Click to expand...

I don't see any way the EFI fuse could possibly affect the fuel gauge's behavior.

Project_13 said:

havent checked up on this thread lately and unsuccessfully, i havent found a way to fix my problem. i was thinking of getting new fogs or rewire them somewhere else.

out of curiosity, i looked over the elbow mod guide again and noticed that it recommended that i remove the EFI fuse while doing it and install back after its done. possible cause? o_0

Click to expand...

Al that does is reset the computer so it can learn about its new intake...no possible connection.