Hi all,

My truck is a Mazda B2200 model 1990. When the gas tank is just fully filled, the fuel gauge shows full for half a day. Then after that it shows empty ( of course still plenty of gas in the tank ). I can live with this by filling up the tank every week. But it is a pain since I never know for real how much gas I still have. Here are my questions:

1. Is the fuel gauge defective (thru what was described) ?

2. If it is, how to replace it ?

I'm open for all advice for I do not know much about car repair.

Best regards.

 

A couple of things here...what size tank does it have, and how many miles do you drive it in half a day? And when you talk about still plenty of gas in there, are you talking maybe a gallon or two - or as much as a half a tank?

Kay

 

Adding to what Kay stated, you'd have to get into it with a wiring diagram and an ohmeter to see if the gauge or the sender (likely the sender in the tank or a ground) is bad.

 

Hello Kay,

It relates to time but not how much I dive ( or how much the gas in the tank is consumed). For the "half day" time frame. I just drove a total of 20 miles. So, even though it is a nearly full tank, tha gauge still shows very low or nearly empty. The tank size is about 14 gallon if I remember correctly.

And Joe,

It sounds to me your suggestion is to by the manual and use the (ohm) meter to measure. But where should I start measuring ? At the fuse area of the gauge circuit ? Please let me know.

Please keep your ideas flowing in.
Thanks

 

Check autolibrary.org below.

 

Most likely is fuel sending unit, in the fuel tank. Fuel sender, fuel sending unit: I'm going to update that pasted below:
Disconnect cable release and the two rubber hoses at the gas fill assembly (loosen and raise bed slightly [see below] to remove the larger one).
Remove the three 17mm-head bolts on the passenger side bed frame.
Loosen the corresponding bolts on the driver's side, about about 2/3 of the way. Use a 16 inch 2 x 4 on a floor jack to lift up the passenger side of the bed Tighten the jack, and up tilts the bed. I used a 1/4 inch drive ratchet, with 1/4 inch socket and a #2 Phillips bit (and two hands to hold it straight). All mine loosened, but maybe because I'm in Arizona there was no rust; I replaced with 7mm head hex head screws (4mm thread x 8mm long, with a wavy washer). Clean the sending unit and bend the contact arm in a little. To line up the bed so I could get the three 17mm head bolts back in on the passenger side, the bed needed to be jacked up a little, then I could use my weight to shift the bed a little from one side to the other.