odd fuel gauge issue?

[Workin' Rig]

For some reason my fuel gauge wont come up untill ive driven a mile or two. Its just sits st the resting point below "e". Also i think its 1/4 tank off (ie reading a 1/4 when its really a half) cause when i fill it it only goes to around 3/4.

Do you guys think it may be a sending unit? Or clusted? Or maybe wireing?

 

[m78]

Go the cheap route first and check all the grounds .

 

[jebadiah04]

Maybe its sinking or gummed up?

I would check grounds first too. Cheapest fix and easiest.

Sent from my mudwhistle via lemmiwinks.

 

[Workin' Rig]

Where are these usually grounded? Is there any besides the one by the tank?

 

[m78]

Where are these usually grounded? Is there any besides the one by the tank?

Thats a good question. I'd start by searching in Duncans scans. Dennis could probably tell you with out blinking an eye.

 

[fatherdoug]

If ground issues don't solve the problem, then take a look at the float on the sending unit. If there is a SMALL hole in the float then it will be just heavy enough to work intermittently or show abnormally low. That was my experience. I didn't think it was the float, beacuse it would still work occasionally. Over a period of time, the float finally "sank".

If you have a midship tank, the float can be pulled without pulling the tank.

 

[Mil1ion]

Check the wiring and ground connection of the wiring that comes out of the sending unit.
My guess,the rust is screwing up the grounding ability.

The tank grounds through the SU ring .


Some ppl mention a faulty float but that rarely happens.
I trust the temp gauge woks fine?

 

[Workin' Rig]

Actually all the gauges except for volts are a bit screwy. Sometimes theyll all go up about 1/8 or so in unison. Or go down in the same manner....

Maybe i should redrop the tanknand clean the grounds and replace the sender and retainer...

And thanks for the diagram. Alot simpler then what i figured

 

[Mil1ion]

If the other gauges are abnormal then pull the cluster and check the gauge connections for corrosion, the ICVR for putting out a pulsing 5 volts, the ground strap to the dash chassis.
The Icvr can be checked at the temp sender wiring.

Process of elimination is required.

I have diagrams for what I mentioned. Just ask.

 

[Workin' Rig]

Ok thank you. If i get a chance ill tear into it this weekend. What about replacing the whole cluster? Ive heard 80s Evan ones will bolt right in and are better?

 

[DNFXDLI]

Less prone to the plastic deteriorating ...but going over what you have and cleaning it up is cheap and generally effective.
I'm doing that on my build.

 

[Workin' Rig]

A ground issue might explain why my dash light on that side with the fuel and oil pressure gauges is really dim. Electrical is not my fortay