Hi, 91, w/305, throttle body, all stock.


The car started to run really rough a few weeks ago, to where I had very little power (couldn't get the car over 35 on level ground)... almost wants to stall but doesn't. It cleared itself up a few days later, and ran absolutely fine until a few days ago, when the problem started again. I am thinking it could be the fuel pump, an injector, or maybe something with the TB. In any event, I noticed something strange today.


When the problem started a few days ago, I had less than 1/8 of a tank of gas. Today, the needle was practically on empty (makes sense; I drove around a bit), and pulled into my gas station. I added 10 gallons, and now my fuel tank says it is completely full - the needle is actually over the F line. This doesn't make sense; the car has a tank that is over 15 gallons, and I have never noticed the fuel gauge acting this way, and reporting that there is more gas than there is. What I am wondering, before I bring the car to a mechanic, is whether or not this could somehow be related to the issue I am having? Not sure how, but figured it was worth asking.


Thanks in advance.

 

i would agree it sounds like a fuel pump. did you test pressure? fuel level sender is on the same mount as the pump so it could be pump or wiring to it.

 

Thanks.


No, I didn't test the pressure. I don't have a pressure gauge.


Wiring to the pump would seem to make more sense; if the fuel pump was the issue, would it have just fixed itself? On the other hand, if there is a frayed wire or loose connection...


So, does the gas tank and fuel gauge potentially factor in here in any way?

 

gauges act weird when they get old ?if its not exspencive buy a fuel pump an try it ,or have someone look at. check the wireing if you can ,they can tell you better if you don't have the right tools ,then if its simple not hard then fix it ,then you can do it yourself ,but gauges act up my 95 runs out at quarter tank ,so I know when I get to a half tank its time for gas ,in your case you know full will be way past full mark a lot of them do it ,an its better then not working at all,but i don't think the guage has anything to do with it ,but mabey it does going back to pressure

 

the gauge float and fuel level sending unit is on the same mount as the fuel pump. wires for both come out the same area. have a look here 4th Gen LT1 F-body Tech Articles

 

his 3rd gen is the same as the 4th gen ,yes I know float controls empty an full