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Should be picking up a new-to-me '87 SR5 22RET on Friday in Central FL. It seems that all of my '87 Turbo 4Runners have bad fuel sender units - the fuel gauge doesn't work. I plan to drop the tank and see if I can fix it - hopefully a stuck lever and not a bad wire. If it is shot, anyone know where to find a used/new one I could sub in?
Should be picking up a new-to-me '87 SR5 22RET on Friday in Central FL. It seems that all of my '87 Turbo 4Runners have bad fuel sender units - the fuel gauge doesn't work. I plan to drop the tank and see if I can fix it - hopefully a stuck lever and not a bad wire. If it is shot, anyone know where to find a used/new one I could sub in?
Not sure about the turbos, but I pulled my fuel sending unit in an 89 4runner by lifting the back seats and going through the top. No need to drop the tank IIRC.
Update: I picked up the truck a month or so ago and have been overhauling it. 99% of the restoration work is now done and this is one of my final projects. Remember that this is a SR5 Turbo Automatic with a digital dash.
As as it turns out, the fuel gauge actually does work. But it’s odd:
- Fuel gauge shows Full Bars on digital dash from 0-100+ miles
- After 100-150 or so it drops from Full Bars to Zero Bars (empty)
- From 150-250 or whenever it is actually empty, it shows Empty with the Fuel Light on
My theory is that the float on the fuel sender is getting stuck in the middle of its cycle (cannot rise all the way up or drop all the way down) due to age. My prior ‘87 Turbo didn’t work at all, so at least this one works in the middle range.
Should I pull the tank and check the float to test my theory? Or due to the way these were made, is my guess flawed and i’d just be wasting my time?
Last edited by Charles4x4; 11-21-2017 at 08:05 PM.
... lifting the back seats and going through the top. No need to drop the tank IIRC.
Charles4x4, Checked if you can do same as this?^^^ No need to drop tank. I think dropping tank is only necessary on the pickup.
Originally Posted by Charles4x4
...Should I pull the tank and check the float to test my theory? Or due to the way these were made, is my guess flawed and i’d just be wasting my time?
I haven't looked at FSM about testing the gauge, but I think the float/sender simply presents a certain electrical resistance to the gauge circuit. Resistance varies with how far up or down the float is. You might be able to test the sender by measuring resistance when you know tank is near empty and when full. Compare with what FSM tells you.
Charles4x4, Checked if you can do same as this?^^^ No need to drop tank. I think dropping tank is only necessary on the pickup.
the gauge sending unit is not accessible via the underseat panel. only the fuel pump is accessible via the panel. the tank must be dropped to remove the sending unit.
Charles4x4, Checked if you can do same as this?^^^ No need to drop tank. I think dropping tank is only necessary on the pickup.
I haven't looked at FSM about testing the gauge, but I think the float/sender simply presents a certain electrical resistance to the gauge circuit. Resistance varies with how far up or down the float is. You might be able to test the sender by measuring resistance when you know tank is near empty and when full. Compare with what FSM tells you.
Thanks, I had heard you can only access the fuel filter through the rear senate (not Sending Unit), but its wotth a try!
Per my reading, you’re exactly right. The float is most likely dirty at top and bottom and resistance isn’t reading correctly. See post from Maco35 here if you want to learn more: https://www.yotatech.com/forums/f114...repair-252091/
Last edited by Charles4x4; 11-22-2017 at 04:36 AM.
the gauge sending unit is not accessible via the underseat panel. only the fuel pump is accessible via the panel. the tank must be dropped to remove the sending unit.
Shoot, that’s what I had heard too. Thanks for saving me some time.
Update: here is the proper sequence to get to the fuel sending unit on an ‘87:
1) Disconnect negative terminal on battery
2) Lift access hatch under rear passenger seat
3) Disconnext fuel filler and breather hoses and plug them with rags
4) Remove fuel tank skid plate (6 12mm bolts)
5) Drain fuel from tank
6) Remove 6 12mm bolts holding fuel tank up
7) Use floor jack to keep front of tank higher than rear so you can access fuel sender from rear
More pics. This is the sender you’re trying to get to - it’s back a little ways behind the fuel pump you can easily access through the hatch. It’s much smaller than I was thinking.
Last edited by Charles4x4; 12-01-2017 at 02:05 PM.
Now here is my problem. From studying the sender, it looks like the internal wiring in the middle is broken and the exterior housing is rusted. While it somewhat works, it’s probabky close to the end of its life.
Since this is a discontinued part, I was trying to fix it but I don’t think it is repairable. I’m not even sure I can open it up without destroying it - seems to be riveted together. Agree?
if not, where can I buy a new one for a Turbo that works with the digital dash?
Last edited by Charles4x4; 12-01-2017 at 02:04 PM.
This is the best I could do. After cleaning the lower half really good (getting the Black gunk off so the wires become shiny again), I got resistance up and down although it jumped around some due to the broken wires. It’s reinstalled so we’ll see how well it works.
Update: I haven’t used a full tank yet, so not a full report. But the sender seems to struggle at the top of its range (half to full) but i’m Hopeful the bottom half (which is what really matters) will prove functional.
10-08-2017, 01:48 PM
