Can no one help me?

[EdensVision]

I am trying to find out why our ford taurus stalls when it's at half a tank or lower, and seems to no longer stall when it get's filled up. As well if there is any link to why my engine light comes on after oil was put in, and now runs a bit rough and stalls as well more now, even when tank is full?

Signed desperatly needing some help or advice

[PSU4x4]

Have you looked at, or had someone take a look at the Fuel Pump and or replaced the Fuel filter? Sounds like that might be what your troubles are.

[UnexplodedCow]

You might have a lot of rust, dirt, and corrosion in your tank, or, you could have pressure buildup causing a vapor lock. Do you hear pressure blow off when you take your cap off at the gas station?

[JLU]

try replaysing the gas cap these tanks are whats call a presure tank if theres no presure in the tank you will at times start having problams like what you are having if that dont fix it have the automatic feul shut valve checked at your local ford delear.

[JLU]

also it might be your sending unit in your gas tank.

[UnexplodedCow]

Since when are gas tanks supposed to have pressure in them? I understand the evaporation of gas can cause pressure, but isn't that why Ford put a check valve in the gas tanks? Wasn't that to bleed off the pressure the evaporated gases cause?

[garync1]

Originally Posted by UnexplodedCow

Since when are gas tanks supposed to have pressure in them? I understand the evaporation of gas can cause pressure, but isn't that why Ford put a check valve in the gas tanks? Wasn't that to bleed off the pressure the evaporated gases cause?

I dont think there so much as pressure but vacuum in the tank if they get real low you sometimes here them hiss when you take the cap off and if you leave the cap off sometimes it will trigger a mass vacuum leak on the obd code. you may want to check the fuel pump and filter first check the gas cap for cracks. Check the IAC to make sure its clean and not sure on yours,have the fuel pressure reg tested if so equiped. and Have the fuel pressure test as well.Hope this helps..Gary

[UnexplodedCow]

I don't know the Taurus gas tanks first hand, but I do know the Tempo and Escort ones, and both of those just have a hose that connects to the top of the gas tank so pressue is always equal with the atmosphere. So, at least in those cars, the fuel pump just pumps fuel from the tank, and any expansion pressure/negative pressure is relieved by the breather tube.

But, on the original note, I doubt it's the fuel pump. If your engine light came on, and it started running rough even with a full tank, I'd say get the engine checked.

[Slick19892000]

I have a '79 ford f-150 and almost the same thing happened, but only an speeds at over 50 km/h. I replaced the fuel filter and it runs as good as ever.

[bowlerguy92]

It sounds a little bit like it may be the fuel pump and the fuel pump does not have enough strength to pull up any gas lower than half a tank, in which case i would check the fuel pump for leaks.