Before I start I have read from several sites about this and haven’t found this specific issue yet. I have found some close and I will mention that.
The problem. Car is a 2002 gt 5 spd. 3.55 gear, intake and clutch are all I know that’s on it. Drives and shifts strong. 142k miles. I can drive it down to 1/8 tank and when I fill up it has yet to take over 9 gallons to full. I’ve looked up and found that it has a 15.4 gallon tank. I’ve also read that most people put in 12 gallons from 1/4 tank to fill up. I am getting between 199-235 miles per tank and averaging 22.5-23.5 mpg. This seems to be about average from what I have read, except for only taking 9 gallons max from 1/8-1/4 tank.
My guess is that it’s either a sending unit issue, or that the hose running from driver to pass side of the saddlebag tank is disconnected, or clogged. I am wondering if anyone else has had this scenario where it takes far less duel to fill up than the gauge would indicate it needs. Any help and/or advice would be greatly appreciated. I have only owned this car for less than 2 weeks and have driven it everywhere with no issues aside from this confusing fuel thing.