94 LeSabre starting problem

[TJAndrews]

94 LeSabre, 88K miles. Twice now, while sitting level in the driveway, the car won't even fire when cold. Fuel gage reads just at the upper point of the yellow mark. Add 2 gallons of gas and it fires right up like nothing was wrong. It takes a total of 15 gallons of gas to fill up, including the 2 gallons I put in to get it started. Manual indicates an 18 gallon tank, so there should have still been 3 gallons in there - plenty for a start on the level.

I suspect a weak fuel pump. Am I off base here?

TJ

[spinne1]

Fuel pressure should certainly be checked and can be done so easily with a fuel pressure tester found at any auto parts store (not too expensive). If I had to guess (and apparently I do) I think it has nothing to do with the fuel pump or the fuel, but rather a crank position sensor, ignition module, or possibly the main computer. Nonetheless, it is a guess and should not be acted upon. First check the most obvious, which is fuel. If all is well, then check spark via the things I mentioned. Also, if it only happens on a very low tank, wait until the problem reoccurs before testing the fuel pressure or you might not get an accurate test (in other words, run the fuel down to almost empty first).

[TJAndrews]

Since all I had to do was add some gas to the tank to get it started, and since the car works great other than that, it's hard to believe it would be anything but the fuel system somehow. Another thought I've had is possible damage to the bottom of the tank pickup tube, so that the car sucks air with 3 gallons still in the tank. But the thing is, it didn't start like a car that had been out of gas, a car that had to fill the line with gas before it could start. It cranked over the normal number of times it usually takes to start when cold, about 5. And, it ran perfectly after it started, no skipping as you might expect if there were air bubbles to work through the system.

It's all very odd. I probably should just take it to a shop.

TJ