98runner210

I thought my sending unit was bad. I replaced it and same thing. I had a few gallons in the tank and it filled up with 13.5 gallons. Wouldn't take anymore. Is there some sort of vent or anything? I would think if it was blocked I'd have trouble filling it up all together not just stop when it is a few gallons shy of being full.

toy_tek

Driven over any big rocks lately? Last time I did I mashed my tank up a bit and lost capacity.

98runner210

no its fine everything is connected too.

Adam F

Doesnt it have a 17 gallon tank? You put 13.5 in and said you had "a few" gallons still in ther.....sounds to me like the tank is full.

Or are you saying your gauge isnt reading full?

98runner210

The gauge isn't reading full and it isn't taking as much as it used to. When I was on empty it would take about 15 gallons to fill up. This, time I was a little past empty and it only took 13.5 to fill up. So the gauge is accurate and the tank isn't full.

Also before I put the tank back, I connected the sending unit and manually moved it. The gauge responded accordingly.

Fo-runna

For what it's worth, I can put 18+ gallons into mine when it's completely empty. The pump usually stops at 15 gallons and I have to nurse it from there.

98runner210

Mine has to be some sort of vent problem. Does anyone know how the tank works in ours?

MARSHALLMAY

carry some gas in a can around with you and see how many miles you get between gage empty and stall out.

Albert.G

mikes19984x4

if i'm correct, the 96-02 4runner's can hold 18.5 gallons...but that's odd about holding "less" fuel...

BajaRunner

Donno, I only can get 15.5 in my tank, and that is after its stuttering from being so low.

98runner210

i know for sure the tank isn't full. what could be stopping it?

98runner210

bump...... any ideas?

Roadtripr

How do you know the tank isn't full?
Either the sending unit is calibrated a bit differently or hitting something (a baffle?) since you can get it to read full. Try keep filling slowly and you can fit a little more in the tank. Also did you drive since your first fill up. I find the reading change as the tank get bumped around and the destribution changes in the tank.
Try see how far you can drive past the empy light coming on (bring an extra tank with gas to make it to a gas station).
My gas light comes on at about 14 gallons. I typically drive 50 miles past that and still only get 16-16.5 gallons in the tank.

Fo-runna

Well if you are putting only 13.5 - 15 gallons in it, it's not full. It's an 18 gallon tank. Like I said, when I fill up, the pump stops at 15ish gallons. I really have to nurse it to get up to 18 gallons... takes forever but you get a full tank. Try it.. fill up super slow after the pump clicks off.

CS4Runner

I agree with Fo-runna. I think he has it nailed. When the pump cuts off I should be able to get at least three more gallons into the tank going slow and easy. I think this is also the problem when people complain about miles-per-tank. They aren't really filling up the tank completely.

(One interesting thing though and I've never figured this out for sure, although it has to be the location of the vent which is discussed in detail in some threads, is that sometimes I can only get one more gallon in after the pump cuts off. Either one or three but it should always be three more gallons.)

98runner210

something had to of changed. It always took about 16 gallons on E, now it only takes 13. It hasn't been this way since I owned it. I found in a search, a Tacoma that wouldn't take more than 4 gal. Something to do with the charcoal canister. I don't think this is my issue

Roadtripr

Don't overfill the it could affect the charcoal canister. I did it recently and that gave me a wrong gas gauge reading and I didn't trust the gauge for the rest of that tank. I wonder if this could have affected your first tank.

Miles per tank means little (IMHO) until you fully run it dry.

http://www.larsdennert.com/4runner/fuelsender/index.htm
https://www.yotatech.com/forums/f2/3...em-pics-60260/
http://en.allexperts.com/q/Toyota-Re...rrect-1999.htm

Good luck

98runner210

i appreciate the posts but I am sure the tank isn't full.

2 different sending units and both read exact same mark when "full"
tested unit to make sure gauge will read full
always took 16 gallons now only 13
reduced mileage per tank

again i appreciate the help but i am looking for causes not anymore "are you sure it's full?" posts.

98runner210

I wonder if there is something wrong with my charcoal canister and that is causing problems filling up. It may be related to my rough idle and flashing check engine on the highway.