Here is a picture of the new pickup tube and sender (left) and the original tube and sender (right). Swap the fuel pump to the new sender.
4/4/04
Lately my fuel gauge has been going nuts and completely inaccurate. It has always been off some with the fuel light coming on and there still being 5 gallons left in the tank. These days it wildly varies and sometimes moves back up from 1/4 to 1/2 full even when the tank is empty. I decided to perform the Toyota TSB EL010-00 and pay for the parts since my 4Runner is out of warranty. That TSB is located here: Instruments - Fuel Gauge Inaccurate.htm See also Fuel Gauge - Testing and Inspection.htm and Fuel Guage Sending Unit - Testing and Inspection.htm <2008: I had Toyota replace the dash circuit but my guage was still inaccurate. I then performed the Instruments - Fuel Gauge Calibration Procedure.htm with the nose of the 4Runner pointed slightly downhill. This appears to have improved the accuracy of the gauge.>
My '99 only needed Sender parts and not a new dash circuit. It is possible that my cluster IS screwed up because sometime ago I did a Fuel Gauge reset hoping it would make things better. If anything, it got worse. You can refer to the TSB above for the parts to order, but all the parts are not necessary as I found out. I originally ordered #83320-35590 Fuel Sender, #77203-35461 Pickup Tube Assembly, #77169-60010.
Removing the fuel tank is straight forward but a bit time consuming. Perform this task when the tank is close to empty. Jack up and put jack stands under the rear axle. Remove the Fuel fill cap to relieve pressure. Disconnect the fuel and return lines making sure to remember which goes where. Disconnect the the large fuel fill hose. Disconnect the skid plate making sure to leave the middle front screw holding the tank on. Since I had the skid plate out, I pounded the edges near the driveshaft to help reduce the incessant rubbing. Remove the remaining bolts on the tank while supporting the tank with a floor jack. Lower the tank a bit and disconnect the fill return vent hose, electrical sender connector and a wiring loom that is attached to the tank. Remove the sender and follow the TSB.
Here is a picture of the new pickup tube and sender (left) and the original tube and
sender (right). Swap the fuel pump to the new sender.
The new sender attaches to a different spot than the old one. It also has a shorter arm.
What is significant when looking at the two senders is that the new sender measures the
fuel level from inside the tank baffle. The old one measures from outside the baffle.
The baffle inside the tank traps fuel so the vehicle will run on an incline. At the bottom
of the baffle is small hole with what appears to be a one way valve. Fuel gets in but
doesn't get out.
Now you may be asking yourself what the difference is between the new pickup tube and the
old one. Not much. The only noticeable difference I can see is that the fuel filler vent
line is not as long on the TSB version. This effectively allows more fuel to be pumped
into the tank before the gas station pump stops. If these parts
hadn't been special order, I would have returned the new pickup tube and simply cut the
original one down a bit. If you want to save yourself $90, don't order the pickup tube and
gasket. You can simply shorten the original one. Make sure
not to leave any shavings that might end up in the gas tank. I drilled another hole in the
breather just below the electrical connector to allow even more fuel into the tank when
gassing up. There is still plenty of air space left for expansion in the tank. My gas tank
was also rather mashed and the original sender somewhat bent. I had to pound the tank out
from the inside some so the new tube would fit.
So, will it help my fuel gauge issue? Time will tell.