On my HA3 truck the fuel gauge only goes to about 80% after filling up since it became colder. Before it always went to full and moved properly. Now when the tank is full it stops at max. 80% of full and then goes down when the tank level goes lower. Anybody had such a problem already and how did you fix it? I fixed that some years back already on my old BMW, where the fuel level sender inside the tank is a very simple design, looks like the same design is used on the Honda cars with a simple float, item 6, 37800SJ6003 https://partsouq.com/en/catalog/gen...wA$&vid=119004&cid=183&uid=4550&q=HA3-2330294 Usually the lever get's stuck when parts corrode inside the tank. Will try to fix it in spring when it get's warmer, but in case someone already did repair it and has some hints, let us know.
Found pics of the parts in the Japanese Yahoo auctions 37800-SJ6-003 , price about $70 for a new genuine part https://page.auctions.yahoo.co.jp/jp/auction/p549196311 Monotaro Japan online shop has an aftermarket new part for about half that price https://www.monotaro.com/g/01569008/
I just got an acty service Manual in the mail today. I’ll take a look and see if there is any info in there about a fuel gage tonight when I get home. Lee
There may be a voltage regulator on the gauge circuit that isn’t letting the gauges see normal voltage when the regulator is cold. Is the temp showing low also?
Temperaure gauge for coolant is working normal as before. I assume it is a mechanical thing, the float mechanism inside the tank is probably the problem in this cold weather. Started when weather became colder, before it worked normal. That is a very simple float system as shown here in the pics https://www.monotaro.com/g/01569008/ But I will wait till spring when it get's warmer, not yet sure if it is easy to remove this float without removing the tank. The unit is located on top of the tank opposite of the refuel pipe/lid, as shown here https://autoparts.beforward.jp/detail/Engine---Components/Fuel-Tanks/PA01522540/ 2 wire connections should be o.k., as it works except for the tank full display, just moves up to about 80% full, not 100%. Thanks for the hint.
I’d trace the wiring, and wiggle all the connectors and clips before I dropped the tank. The cold weather may have caused issues there. The float mechanisms are pretty bulllet proof, and rarely fail. But, I’ve got a scissors lift, so it’s lots easier to get at the wiring, and would be lots easier for me. Just had a brain flash: It might be easier, if you can round up a helper, to lift the bed off, then to drop the tank. Depends how rusty things are. The bed is held by six or eight bolts. I pulled the bed off my 77 Toyota Hilux three or four times, to install a lift, and upsize the fuel tank to 40-gallons.
I have a pit and a Maxjack lift, so no problem. Will also check the wiring as suggested above. But will wait till it get's warmer, no need to hurry. Against the wire problem theory is, that the fuel gauge works properly, except for the last 20% (to completely full) when tank is full. Gauge indicator goes down when tank level goes down and it goes up again when I fill up, just not to full completely. No rust problems here on the Pacific side of Japan, tank is rust free.
Had a look at it today when I had the Acty on the pit. The sensor is mounted on top of the tank next to the fuel pump towards front of the car. Very tight space, maybe 4 inches, just can get a hand there and could pull the cable connection and tested it. No problem, also no corrosion at all there in the tank area. So the problem is definitely the float of the sensor inside the tank (the mechanical part). But for that I have to drop the tank a bit to have enough space between tank and chassis to be able to remove the sensor from the tank. I will postpone that to spring when it gets warmer, no big problem.
Fixed. As I assumed the float was stuck, I tried a simple fix in the hope it would work:lifted the truck on the rear with a jack that all fuel inside the tank went to the front of the tank where the float / sensor is loacted, in the hope that some movement inside the tank would unstuck the float. Went to the gas station, filled up 10 liters and the gauge shows again full. Problem solved.
