Gas Gauge Hijinx

I've had this pattern going on for awhile...

When I fill up my tank it reads full at the gas station and while I drive home.
I park in my driveway which is a pretty steep incline.
The next day when I start the truck the gas gauge is on empty with the warning light on.
Once I get on the road and start driving the gauge slowly returns to normal.
After driving for a bit and the gas level drops the gauge works fine until I fill up again.

Anyone else having this issue?

 

Never dropped to empty with warning light but my fuel gauge will sometimes drop from full (correct) to somewhere above a half tank. The first time was a WTF moment... stopped and looked to see if gas was leaking. The gauge will typically soon recover to the correct reading but sometimes not till the next day. Curiously, it only occurs when the tank is near full. Never drops from say a half tank reading to a quarter. Anyway.... since then I've made it a habit to reset the trip mileage and refill accordingly. The imperfections of a 25-year old truck....

 

My gas gauge always drops when the truck sits. Longer it sits, the lower it drops. Slowly rises as I drive for 10-15 minutes. Don't know if it's the gauge cluster or the fuel pump assembly. Either way it doesn't bother me enough to investigate any further and I can live with it. Yours sounds like it would be annoying. What happens if you park the truck pointing the opposite direction?

 

The fuel gauge works using a basic sender, it's a resistance circuit. Almost all vehicles use an internal float system or a pivot arm, where the circuit wire/contact runs across a contact pad of some sort. If you get corrosion on any part of that contact pad, it will cause a "dead spot" in the circuit, which will cause zero (or out-of-range) resistance on the circuit, and the fuel gauge will typically drop to E.

It sounds like youre sender is having this issue at that specific spot on the contact/slide surface. The only resolution, depending on your year/configuration, is to replace the fuel pump assembly, which contains the integrated sender.

 

Hey Shifty,

In your experience do these eventually crap-out and die completely, or does it just continue with an intermittent problem for years?

Also, if I need to replace the unit, is the fuel pump assembly still available from Toyota, or am I looking at an aftermarket unit?

 

May continue for years if what I'm desribing is the issue. I ran with similar in my dad's pickup for at least 10-12 years. Could've been something as stupid as you had a little dot of water or debris land on the contact pad, and it won't happen again. If it doesn't bug the shit outta you, don't bother. But also expect that the fuel pump assembly will probably be disco'd by Toyota in the next 3-5 years. It's available for most of the newer trucks still. And on some trucks you may be able to buy the individual part.

Someone posted a pic of what the corrosion on their slide looked like. I wish I could find it.

 

Thanks for that. If the part isn't super expensive I may buy it now and keep it on the shelf. Do you know if the part # is the same for all of the first Gens? Mine a 2005 Access cab v-8 4x4.

 

It's not all the same. PM me your VIN and I'm happy to see which you have, and lookup your parts/options.