06Rubi

Ok what does the low fuel warning module do then? When the light isnt on it seems to run better and smoother but once the light comes on it seems to have a slight stumble

HACKGT350

my low fuel warning modual is just hanging out from under my dash on the passenger side for some reason i just zip tied it back up so no one kicks it or breaks it

06Rubi

i guess my issue with it is why does the car seem to stumble and not run as smooth as it does when the light is off. So this module has nothing to do with the way teh car runs just whether or not the light comes on or not?

HACKGT350

it could be in your head that the car is running bad with the light on and the modual has to run from the tank to be able to pick up a reading on the low fuel so it is part of the pump in a way its all one big sending unit

06Rubi

When the light is on teh rpms drop a bit and then itll idle up then drop back down. I figured that it has to be something with the pump not putting out enough and that is where the stumble i feel comes from

06Rubi

does anyone know what the fuel pressure should be and how hard is it to test? Sorry this is my first mustang and fuel injected toy

HACKGT350

dont sweat it thats why this forum is here so you can learn i really dont know what the fuel pressure is but i think it sounds like your fuel pump is starting to get a little week i would run through this tank of gas and put your new one in its not a hard job just a pain in the *** on the ground and if its still does this after you put it in it could be clogged injectors or even wiring a little messed up

svt99redcobra

Hell i wondered why i've never seen a light pop on.

06Rubi

When i bought the car it wasnt on but only had a little gas in it so i put gas in it drove it home and no light. The car did sit for quite a while without beign driven too much so i thought maybe i just had some bad gas so i added stuff to take water out of the gas. To test it i just need to get to test guage from like autozone and screw it into that schrader valve and turn over the car or how do i go about that?

Joel5.0

Install gauge to schrader valve, start the engine, pressure should be 30-40 psi with vacuum line attached to the fuel press. regulator and 40-45 psi with vacuum line disconnected from the FPR....you may also want to check the ground strap connected behind one of the cylinder heads to the firewall....that ground could also cause some problems.