I primed or attempted to my lines. wanted to check it was getting through so disconnected my return line. jumped the connector pump runs there's definitely fuel in the feed line but nothing is coming out return. what causes this? stuck regulator?

 

or will it not return until it's running?

 

The Fuel Pressure Regulator (FPR) operates somewhat linearly based on vacuum from the intake manifold. More vacuum means the regulator opens at a lower fuel pressure. Less vacuum means more fuel is needed, so it opens at a higher pressure. Under normal conditions, the FPR will open once there is sufficient fuel pressure in reference to the amount of vacuum it sees coming from the Intake Manifold. Priming the system means the FPR sees Zero Vacuum (Ambient Pressure), so the regulator will open at a significantly high pressure (considerably higher than an idling engine drawing in ~30InHg of Vacuum). I want to say around 70-80psi, but don't quote me on that.

Check the FSM or do a quick search for the exact numbers.

 

so it would take a long time of the pump running during priming for it to open and flow through the return? I had read bout it opening and closing based in vacuum but it mentioned nothing bout priming. so thank you for clearing it up

 

your lines are reversed, pump is dying, fuel filter plugged or pump isn't getting enough voltage.

the FPR doesn't "open", it bypasses a certain amount of fuel always. it never holds the return system shut at any time so you should always have fuel coming through.

 

if lines were reversed when I hadreturn off it would shoot fuel out the firewall hard line?pump could be dying but it is pumping? fuel filter is brand new but I did make the amateur mistake of putting it in upside down first. I've put my battery on charge last night might buy another as it's a it questionable. it was out of another car that it wouldn't charge in but have since charged with a charger and seemed ok.

 

it shouldn't be coming out of the hardline off the firewall if you have the fuel lines disconnected, that would mean you somehow installed the pump onto the return dump line on the pump housing inside the tank.

 

OP, what did you do last to the car, in terms of work, before you started having problems?

Did you leave a clamp or hose blocked off somewhere in there?

 

I thought you meant at the pump having the lines reversed

 

i meant the lines to the engine, you can't feed the pressure regulator in reverse, it will virtually shut off fuel flow.

the line off the fuel filter should have fuel coming out of it with the key on, crank. that line should be attached to the front side hard line on the rat's nest. with rear line disconnected you should see similar results when cranking the engine or jumpering the fuel pump test connector. the rear hard line joins to the hard line at the firewall just rearward of it.

if fuel is coming out of the hardline at the firewall then something is wrong inside the tank or you mixed up the lines at the top of the sender.