Gas Guage

[droppedHoe]

im having an issue that just started about 2 hours ago.
i knew i had less than a 1/4 tank of gas and was gonna put some gas in after picking someone up from the train station.

well when leaving my gas light came on, no biggie.. i tossed $25 worth of gas in.. just about 10 gallons so half tank...
well when starting the truck after putting 10 gallons of gas in the gas light was still on....????WTF????

i drive a few miles and it slowly made it up to 1/2 tank.. then out of no where jumped up to a full tank... i wish $25 gave me a full tank but it doesnt lol
i park at my house and my check engine light pops on and 2 weeks ago it was just opening and tightening my gas cap... its probably the same thing but i'll get it scanned in the morning since its 2am. but along with the light my gas dropped under the E but i know there's plenty of gas in it.

anyone know what the issue could be? i have a brand new delphi/napa fuel pump in the truck. what could it be???
someone help i dont wanna run outta gas b/c the gauge is fu*king up....

 

[vwbeaner]

your float may be messed up

 

[droppedHoe]

mmmm, whats that?

 

[TqMnster]

The float is that foam type piece on the end of that metal rod attached to the sender inside your gas tank.

 

[droppedHoe]

i have a co worker thats gonna take care of it for me.he said it shouldnt take him more than a hour to do... just gotta find a local shop that has it...
its not the float looking thing on the back of the fuel pump correct??? its a hole different thing???

 

[droppedHoe]

hey guys, is the float a part of the fuel pump or something else in the tank. b/c by description it seems to be the black thing on the back side of the fuel pump attached to the thin metal rod.
i have a warranty on the pump from napa and if thats it i'll go exchange it for another pump.

couldnt pull up the delphi for some reason but it looks exactly the same.
http://www.napaonline.com/Search/Detail.aspx?A=AFPE3508M_0252722878&An=599001+102001+50014+2014365#

is that the floater on the backside of the pump?

 

[My01yuk]

Had the same problem with my 01 yuk when I bought it. It was the sender unit and had to replace the whole fuel pump. The float is part of the pump.

 

[droppedHoe]

thats what i thought. well the pump is rather new and still under warranty at napa so its going back getting a new one.
its only 3 months old

 

[YukonBill]

I am having the same issue with my 01. Gauge reads fine then goes to empty. How big of job is it to replace the sending unit?

 

[YukonBill]

So can anyone that has had to drop there fuel tank advise me on how this is done?

 

[Red Rider]

You may want to do a search. I have seen multiple threads on subject. But it may be your stepper motor. Hi have a drunk gas gauge. It never zeros out at same location. But it seems to work when you turn off ignition, then turn back on. gives your rough reading. I have not yet had balls to let it run out until the 'time to fuel up' light comes on.

 

[YukonBill]

I didn't think 2001 had a stepper motor?

 

[CM Burns]

My 2001 Tahoe did this exact thing. Mine would be at full tank (or at any level), and then the gas gauge would completely drop to E instantly and the gas light would come on.

It started acting goofy few and far between, and eventually it read "Empty" 24/7 and I monitored my fuel amount with the tripometer.

I found out early on it was the sending unit, but since the pump was still functioning I put it off for months until I had the money, b/c unfortunately it is a one piece deal = you have to replace the fuel pump.

 

[ccapehartusarmyINF.(ret)]

find out what the code is
i just finally got my evap system fixed and while i was still having probablems i was having all kinds of fuel guage reading problems and fuel light problems every thing else is fixed now but my guage still doesnt read right it runs outta gas at a quarter of a tank and i get no low fuel warning
are you getting alotta extra hissing when you open the cap

 

[CM Burns]

find out what the code is
i just finally got my evap system fixed and while i was still having probablems i was having all kinds of fuel guage reading problems and fuel light problems every thing else is fixed now but my guage still doesnt read right it runs outta gas at a quarter of a tank and i get no low fuel warning
are you getting alotta extra hissing when you open the cap

I just had my Vent Valve Solenoid replaced in the rear of my Denali and the fuel cap as well. My fuel gauge was fine, but it kept saying "Tighten Fuel Cap"

2 weeks later its telling me to tighten the Fuel Cap (again).. something is def up with my Evap system somewhere

 

[YukonBill]

I have no issues with the evap system and the engine runs fine. there are no warning lights just the issue with the gauge going to empty when it is full. I assume it is the sending unit. How difficult is it to lower the tank and replace the fuel pump unit? Is there a way to find out what pump it has in it before lowering the tank? I would like to order the parts ahead of time.

 

[ccapehartusarmyINF.(ret)]

its not difficult but
you have to get the vehicle of the ground at least on jack stands and youll definatly need an extra set of hands there is two straps if memory serves me and when u undo the first one you need someone to hold up that end of the tank so you can undo the second strap im sure you already know this but make sure u run the fuel tank dry or at least mostly empty or that tank will be awfully heavy when you loosen up those straps

 

[YukonBill]

How can you test to see if the problem is the stepper motor and not the sending unit?

 

[Red Rider]

From what i have seen, you can't test the stepper motor. But most likely, you could test the sender unit. Shop manuals should give you the min-max resistance coming off the sender and you can compare it with what yours is putting out.

 

[1989toddm]

From what i have seen, you can't test the stepper motor. But most likely, you could test the sender unit. Shop manuals should give you the min-max resistance coming off the sender and you can compare it with what yours is putting out.

I'm lurking along watching this thread, as my yukon has the same problem. But can you tell me what the stepper motor does/is and where it's located?