fuel gage

[ChRoNiCPhAnToM]

so im new to the forum but not to tuning im also a member of Acura-Legend.com my cb7 aka the chronic phantom....ive moded some but soon (when check comes thru) i wanna go jdm you know PFM amber spedo. red n white lights and those nifty look'n intersection lights... anyways as long as ive had my car (5+yrs) ive had the same problem my gas dose'nt read below a half a tank... anyone else?? ive gotten really good and guestimating gas i have left and im pretty accurate within 5 miles of it actually sputtering and die'n. Ive narrowed it down to two things... A: the gage its bad or B: the fuel pump/ float. is bad and i dont want to do more work then i have to ...... so based on the feed back ill make my decision to repair one or the other and hopefully i wont have to disassemble both anyways.

[benji]

so im new to the forum but not to tuning im also a member of Acura-Legend.com my cb7 aka the chronic phantom....ive moded some but soon (when check comes thru) i wanna go jdm you know PFM amber spedo. red n white lights and those nifty look'n intersection lights... anyways as long as ive had my car (5+yrs) ive had the same problem my gas dose'nt read below a half a tank... anyone else?? ive gotten really good and guestimating gas i have left and im pretty accurate within 5 miles of it actually sputtering and die'n. Ive narrowed it down to two things... A: the gage its bad or B: the fuel pump/ float. is bad and i dont want to do more work then i have to ...... so based on the feed back ill make my decision to repair one or the other and hopefully i wont have to disassemble both anyways.

I'd say pick up a new sending unit from a car in the junkyard and see if that fixes the problem. Junkyard parts are cheap and if it fixes it then you are good to go. I doubt it is the gauge mainly because gauges tend to rarely break. Disclaimer: I'm not saying they don't ever break, just that it is rare.

Once you get it fixed, be sure to get an average mileage before fillup. I know in my car (H22A Prelude) that I average around 360-375 miles to a tank. My gauge (not a needle, the electric ones in the ludes) skips a few of the icons, so it isn't really reliable.

[Isdoyra]

If you did any mods in the cluster, like new faces or something you might f....d up your gauge ( it happened to me and I didn't even touched it).

If not the float it's messing with you, that one is more likely to malfunction!

[TypeG]

i would also lean towards the fuel sending unit. you can test it with an ohmmeter. it's located under the back seat cushion within the gas tank. later.

[dksix]

I had to replace the sending unit in mine when I got it . It worked when full but never showed that the tank was empty . It was my first honda and I thought I was getting 50 MPG the first week , until I ran out of gas .

[ChRoNiCPhAnToM]

no ive never taken the cluster apart .. my gas light still tell me when im low but i try not to let it get to that point, its just a reminder sometimes.... im lean'n on it it being the sending unit too but i just was testing waters to see who else had the problem cuz my boy's CB has the same problem as me...... thanks for the input fellas

[randomcustoms]

i agree it is definitely the float in the sending unit, mine was doin the same thing so i bent the arm for the float now its almost right so recommend getting one from a junk yard as suggested!

[dksix]

no ive never taken the cluster apart .. my gas light still tell me when im low but i try not to let it get to that point, its just a reminder sometimes.... im lean'n on it it being the sending unit too but i just was testing waters to see who else had the problem cuz my boy's CB has the same problem as me...... thanks for the input fellas

Is that odd that the light would work , but the needle shows incorrectly ? I would have thought that the sending unit would be what also turned the light on . Is there 2 outputs on the sending unit , 1 to send fuel level signal to the gauge and a switch that tunrs the light on ?

[TypeG]

Is that odd that the light would work , but the needle shows incorrectly ? I would have thought that the sending unit would be what also turned the light on . Is there 2 outputs on the sending unit , 1 to send fuel level signal to the gauge and a switch that tunrs the light on ?

yup, you guess right. the gas light usually works, but the needle is off. later.

[TomQuick]

My gauge constantly reads full. I narrowed it down to being the sending unit by unplugging the wires from the sending unit, and turning on the ignition. If the gauge drops to Empty when the wires are disconnected from the sending unit, then the problem is in the sending unit. If the gauge continues to read full with the sending unit disconnected, then the problem is either in the gauge, or a short to ground in the wiring between the gauge and the sending unit.

After pulling my sending unit out, I discovered that it's been hacked apart, and rigged back together. There were at least two splices in the wiring to the float, and the float arm mount was hanging loose on the sending unit structure. It is not at all unusual for the float level to read wrong, while the warning light still works though. The warning light is a separate sensor, providing a simple on / off signal, while the float level is a variable resistance signal controlled by the float.