intermittent operations gas gauge

I had roughly 45 miles on a new tank of gas. I shut down the truck to go fishing and when I came back and drove home I was at half a tank. I originally thought someone stole some gas out of my truck at the boat ramp. On the way home I noticed the gas gauge fluctuating on the way home. It would drop down to 1/4 and back up to 3/4. I went to the gas station and topped the fuel tank back off. It was fine until about 3/4, it has since then dropped down to E and has been there ever since. I have about 200 miles on this tank so far. Looking for troubleshooting procedures, or should I just replace the sending unit in the tank?

Fuel Level Sending Unit - Repair or Replace
A failed or malfunctioning fuel level sender can cause the gas gauge in your 2010 Toyota Tacoma to be inaccurate or read empty or E despite the fuel level.

I'm going to assume I should also replace the fuel pump since I'm in the tank. Thanks for any help

 

I would replace both. Not sure about a Toyota but all the GM fuel pumps I’ve done all came with a new fuel level sensor

 

Yeah, I would do the whole assembly and just do the job once...

Sure as hell if you replace just the sender the pump will go out in a month right after you fill up the tank.

 

Yep, what these guys said. Any good shop or knowledgeable tech will replace the pump with the sender unit 10/10 times. Even more so due to the fact that the pump and sender assembly are a module assembly sold in one.

That being said the only time I would not replace the sender or vice versa is if the pump assembly or sender unit is brand spankin new or has low miles on it.

 

The pump and filter live in a "bucket" inside the tank.

I'd recommend if you're changing the sender and pump to do the URD filter relocation and pump upgrade.

 

Does anyone have a link on how to remove the gas tank? Or a toyota PDF on the removal?

 

I’m sure there’s YouTube videos but they’re all the same.

Remove tank straps, support tank with floor jack, lower tank enough to remove fuel lines and sensors, once free of them lower tank the rest of the way, clean any debris around fuel pump lock ring, remove lock ring, remove pump, replace part(s), install pump with new gasket, reinstall lock ring, lift tank with floor jack to reinstall fuel lines and sensors, lift tank the rest of the way and reinstall tank straps.

 

Or pull the bed off...

 

You’re no fun.

 

Disconnect battery to remove possibility of spark.

Pull the bed (remove tailgate, ((disconnect back up cam if equipped)) remove tail lights, disconnect taillight wires from bed pull the 6 bed bolts) have a buddy help you pick it up and set it aside by the fender wells, it's awkward but not really heavy.

Disconect pump connections.

Use a strap wrench to turn the pump/pickup/filter bucket retainer ring off

Made my own with a 2x4 half an old timing belt and two lag bolts, can post pictures if you really need them.


Pull the pump/pickup/filter bucket out

*Note the bucket top (the part you can see from outside the tank) has a little bit of spring preload and may pop up and surprise you but it's not a lot of pressure it's not going to send anything flying it's just going to *boing!* no big deal.

Easy job just takes a second person/friend/buddy/neighbor/teenager to help set the bed aside.



*Extra tip, grease the gasket when retightening the bucket retainer ring and don't pinch the gasket or over toruqe it or you can have vapor leaks and a CEL/DTC.

 

Excellent post!

 

I ended up dropping the tank, Ive read where you cant access the fuel pump with the DCSB. The pump is under the cab. It was a PITA doing it alone, I had about 10 gallons of fuel in the tank. Those connectors are a pain also, but for good reason. Thanks for the reply, If I had an Access cab hands down I would of removed the bed.

 

I really don't see why everyone is so hell bent on doing an external fuel filter. The strainer is plenty suffice for filtration unless you are really THAT worried about crap entering your fuel system.

I live in California where fuel quality is garbage and despite that I have not personally worked on or seen one car that's gone through our shop that has had clogged fuel injectors due to garbage getting past the strainer.

 

The strainer is the "sock" before the pump that keeps garbage big enough to damage the impellor from entering, the filter is after the pump that keeps junk small enough to pass through the pump just fine but big enough to plug an injector from reach them.

The sock typically doesn't clog, the filter does, and this definitely happens lots of threads about loss of power and long starting on here due to filter blockage.

An external filter does two things, one makes it easier to change as it can now be done with a very cheap disposable part off the shelf from Napa in a matter of minutes without dropping the tank or opening the pump bucket, and two, allows the installation of a larger higher flowing more reliable and or more tolerant (e85) fuel pump.

Injectors even with the filters still get clogged and no amount of injector cleaner will unclog them, after a certain milage it's a good idea to rebuild them and have them flow balanced by a place like Witch Hunter Performance, the night and day difference it made was WELL worth the cost, improved everything about the engine; milage, throttle response, smoothness, power band, torque, starting.

Just because something is working, doesn't mean it's working optimally.

YMMV

 

Never dealt with this on a fuelie engine so it could be different, but one of my old cars with a carburetor and mechanical pump had a bad ground either at the tank or behind the gauge cluster..I forget.

That said, one way around this short term is to use an Ultragauge..as long as you remember to reset the gauge after each fill up or partial fill up accordingly, you'll know how much you have left within half a gallon or so.

 

I know what the post filter is for and what it's primary function is. I've been working on and diagnosing cars for over 15 years now and have seen my fair share of clogged external filters on older cars. Lol.

I run a capable E85 fuel pump as it is without an external fuel filter and can technically switch over tunes to run pure E85 at any point as I am running flow matched Bosch EV14 550cc injectors to handle the extra flow

I could respect what you're saying though.

I don't know. Part of me agrees with the idea of a post filter, the other part of me doesn't. Injectors actually do lose their efficiency over time and if your injectors are clogged up due to mileage and time then there is probably a good chance that you should just replace them anyway due to loss of efficiency issues. It's sort of a lose lose situation, as injectors are in a constant state of duty cycle as long as the engine is running. It's sort of a wonder that they work as effectively and efficiently as they do if you think about it.

 

Perhaps it's the old schooler in me, but I've never loved the idea of a not easily replaceable fuel filter. Perhaps one doesn't really need the external, but it's cheap insurance if nothing else.

 

Not wanting to be Mr. Negative, but:

You cannot "rebuild" a modern gasoline fuel injector. It is welded together during assembly. At the very best you can clean the outside nozzle orifice plate, replace the external O-rings and any snap on tips if applicable. And with the proper equipment you could pull the pressed in filter if it has one and then back-flush (reverse flow) the injector then insert a new filter. Many still have an internal basket filter that cannot be removed as it is around the needle valve. After assembly and setting the body is over-molded in plastic.

Even the Old EV1 injectors flow couldn't be altered after it was set as the adjustment sleeve was staked in place.

I don't see how they can flow balance anything as the adjustment sleeve is inside the injector and set during assembly.




Image below you can see the basket filter on the EV14 Injector needle.

 

Yeah I'm aware of how they're made and sealed up, I don't know the secret sauce behind what they do, you'd have to ask these guys but I can tell you they made one hell of a difference.

https://www.witchhunter.com/

 

I'm glad you are happy with their service they provide. I can even see where injectors with the inlet basket filter could benefit a little. Most of the Bosch injectors have a filter inside around the needle valve that cannot be removed. Not much good other than cleaning the outside and installing new o-rings.

Been working in the injector business for over 25 years... Diesel Unit Injectors, EV1, EV6, EV14, HDEV5, HDEV6