How do you remove the vacuum line off of the fuel pressure regulator to check for gas?

 

What year? What motor?

On my 1993 302, you can just pull it off with your hands. Are you wanting to know how to remove the fuel line?


'93 F-150 loaded and modified!
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1990 4.0
What line do I pull off and where is it located? What does it look like? Never done before. Please explain process on vacuum line and fuel line.
Thanks

 

The 4.0 regulator is mounted on the pass side of the fuel assembly. It is black, and has a small rubber hose attached at the back and a braided hose attached at the top. It is about 1.25" in diameter. It is held onto the fuel rail assembly by 2 8mm bolts.
When it goes bad, it generally will cause the engine to run VERY rich. You can almost watch the gas gauge go down as you drive. LOTS of black soot out the tail pipe.
It's a lot easier to check the pressure with the schrader valve and a gauge. If the pressure is 35-40 with the engine running, vacuum line attached, and jumps up to 40+ with the vacuum line disconnected, the regulator is working. They are unbelievably expensive. $120 at Ford, though NAPA lists the part from another mfg.
tom

 

What if the engine wont run? is there a way to check the pressure with a gauge without the engine running? mine wont start. Im thinkin it may be bad (by another thread response), and dont wanna replace it if I can test it adequately first...

 

On EFI trucks, the fuel rail should pressurize when you turn the key on, you should be able to hear the fuel pump run for a few seconds. This pressurizes the fuel line(rail).

Guy.

 

I had the same problem on my 89 300. It wouldn't start and had no fuel so I tried electrcal side first. Turns out my computer was burnt out. In my opinion it is a lot easier to get a voltmeter or a test light and check the inertia switch, the relays, if the pump runs, that sort of stuff. Just a suggestion. Good luck.
Rob

 

Ok here are a few things to check before going out and spending a lot of money. I just went through this with my 89 F250 351 EFI.
There is a shrader valve on the fuel rail, If you turn the key on and remove the black cap off the valve and push the stem core in with a small drill bit or something you should get some fuel out of the valve, If you are daring you can bleed fuel off intel you hear the fuel pumps kick back on. If there is no fuel coming out of the fuel rail then you want to start looking at the fuel pump relay. Usually if this relay goes bad the fuel pumps run all the time. Next thing to check is the EEC Relay. It is common for these relays to go bad. If the EEC relay is bad or the contacts corroded the fuel pump relay will not kick in. The way I would test the fuel pump relay and the EEC relay would be to turn the key off remove the EEC relay and after about thirty minutes with the key off (one or two beers) plug the EEC relay back in. At this point you should hear the fuel pumps kick in. If the pumps kick in then both relays are good. The next thing that would prevent fuel from getting into the cylinders is the toggleing on the injectors. This is controlled by the main computer. To test this you need a LED (light emitting diode) or a digital test meter. Plug the LED or test meter into one of the injector plugs and crank the engine over, If things are working you should see the LED light up every time that cylinder calls for fuel.

Hope this is more help than confusion.

If you need more help you can e-mail me at cybyrd@btc-bci.com


Cyberbyrd

 

The FPR has a vacuum line so that it can maintain rail pressure a fixed amount above manifold pressure.
If the diaphram in the FPR fails fuel leaks across the diaphram and if you turn key on (so pump presurizes the rail)with vacuum line pulled and off fuel comes out the fpr vacuum port you found your prob.
Simple chack that only takes 1 minute to do.