DRCOFFEE

I'll start by saying I searched multiple sites and 10s of threads but none had the same issue I'm having.

Yesterday after we filled with fuel, the gas gauge only rose up to just at 3/4 tank. I know it's full because I went back and topped it off and still it will not rise above 3/4 tank on the gauge. The gauge seems to reset at the same place if I switch the key on and off. It also moves lower as you empty the tank as it normally should. But now I'm not sure how to read the gauge other than to keep track of the odometer. I also disconnected the battery to reset the computer, but still no joy.

I normally use Mobil 87 octane gas but last week I filled up at Speedway Gas because we had a gift card. I must be an idiot. Anyway, i refilled with Mobil again and added Techron to it. It was on the next fill up that the gas gauge started to act up.

So my take on it is that I should be looking at the gauge in the cluster because the in-tank sender is still sending a reliable signal. it's not pinned on E or F. What should I check next? If its fuel related, what is the chance it will self correct?

enapa

Everything ive read points to the cluster going bad.

DRCOFFEE

I hope it was just some bad gas and it fixes itself with clean fuel..

4biker

My understanding is that there are two types of sending units (or gauge clusters), and the newer ones tend to fail. I'm not sure what year they changed to the more problematic system but I'm pretty sure it was '99.

I've also looked around for a fix for mine ('97) and maybe a bad float in the sending unit? I'd be shocked if one tank of tier 2 gas would send your gauge into a tizzy.

DRCOFFEE

Well for now its back to normal. Just filled up with a fresh tank of gas and the fuel gauge is reading above full again like it should. Fingers crossed that it was just a bad tank of gas.

I remember about 5 years ago Shell had such a high sulphur content it was causing fuel gauges to malfunction and they did reformulate to stop the problem. We didn't use Shell gas at all, but maybe Speedway has high sulphur in their gas.

enapa

Mine works fine when full. Its after 20-30+ miles on a full tank it stops working accurately.

I have a 96.

DRCOFFEE

Follow up. So after that bad batch of gas, the gas gauge problem has never come back. So I'm convinced it was the tier 2 Speedway gas that caused the issue. I would also suspect that continued use of that gas would have ruined my sender. Something for you to consider when choosing where to fill up next time.

On a side note, my fuel pump started to die, taking longer to start the engine on restarts. So when I replaced the pump last week, I found that the newer version of the sender had already been installed by the PO. Getting back to the original topic, it wasn't the failing older version of the sender which the 3rd Gen is so famous for.



Newer style on the left, old style on the right