ok so heres the deal 87 f150 300 six if that matters but i need to know what all can be wrong with my gas gauge and how can i check to rull them out
im 16 and this 350 gallon here in terre haute indiana are really screwn me over
so please help me no matter how obviouis tell me what i could do
thanks

 

What Rear Gear are you running?
As Gearing in the Low 3.00's, lower RPM's, less Petrol consumption, would be better then Gearing in the High 3.00's or Low 4.00's, higher RPM's more Petrol consumption.

What trans, Manual or Auto?
Manuals get inherently better Petrol consumption than Auto trans.

How much extra stuff are you running off your engine, A/C, P/S, etc.?
Any of those Extras or combination there of will cause more Petrol consumption.

 

You didn't say what is wrong with it. Is it stuck full? Stuck empty? Stuck somewhere else? Something I'm not even thinking of?? Let us know then we'll tell you what to check.

 

my bad
im not complaining about the mileage i know it sucks
but im asking wht could b wrong with it
i got some answers in a another area but never hurts to have more
the gauge is burried past F then when it gets close to being time to fill up again it will go back and forth never stoping then stay past E a little after that
if all that makes sense

 

Looks as if the Sensor or the Gauge is bad or you've developed a short from your description, as All 3 will cause the Gauge to Peg in that fashion.

 

The only reliable Ford gas guage is a yard stick.

 

My 79 f150 do that. fun thing I put 2 gallons from touch E now it say half.

I never trust that but if I turn off then turn on not start engine watch where gas if it close to e I go fill tank.

Or drive bad road then gas gauge went bounce not steady.

 

With they key switched to accessory, you can get under the truck and pull the lead off the sending unit above the tank. Have a friend tell you what the needle does as you ground and unground the sending unit lead. I can't remember which way it should go but it should either peg towards E or F on and off. If it does that correctly, then the problem is in the sending unit. If not, it's in the wiring, or the gauge itself.

 

I've never had a problem with mine. They've been 100% consistent since the day I bought it. I can usually tell withing 1 or 2 gallons how much it's going to take to fill it up just by looking at the guage.

 

on my 88, when its full the needle will read WAY past full. when im at a half tank it'll be at F...i know a lot of these 87-91s are like that. from what i gathered it can be a faulty sendor or a bad ground at the main guage cluster.

 

IIRC the sensor that is part of the intank fuel pump assembly is known to have a faulty diode. You've only got a couple of reliable options. Replace the assembly or add an aftermarket sensor. What's happenning is that the sensor effectively degrades to the point of signally full or empty and nothing in between.

I have the same problem in mine. If your know what your average mileage is, then your can determine at what miles you need to refill at.

 

Having a small 1-5 galllon gas can also makes for good insurance if you feel your estimates/driving style may be too erratic. It doesn't fix anything, but it does save some walking.

 

if you pull the pump & sensor you might want to check the flot before you buy the whole thing for about $200. dollars because they are bad about leaking and filling with gas. they leak often enought that ford sells replacement flots,2 in a package for about $7.50

 

k thanks for the info il check it out if i have time this weekend
thanks again guys

 

1989 5sp 4x4, My gauge will read just below full when full, then quickly fall as I drive. I have changed instrument clusters because of a bad temp gauge but still the same. I just reset my trip odometer and fill up around 200 miles, has worked for three years now.