1993 Ford Ranger Fuel Pressure


Old 08-20-09, 12:53 PM
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Smile 1993 Ford Ranger Fuel Pressure

My manual says my working fuel pressure should be 35-45 PSI.
My fuel guage reads 31-32 PSI when it is running. Is that enough pressure? When I try to start the truck the fuel pump does not stop running. When the truck was running right, you could hear the fuel pump come on then turn off after a couple of seconds. Now it does not turn off. Is their something in the computer that tells the fuel pump relay to turn off when you first start the vehicle, or is there something else that controls when the fuel pump should shut off?? Thanks!
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Old 08-20-09, 01:04 PM
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You keep posting the same info over and over in different threads. It gets very confusing when someone gives you an answer..and you don't comment on what they say or ask. It can be very frustrating and confusing to the responders. You had several people give suggestions...but you can't expect an instant response. Most of them are working mechanics who come here as time allows.

If you are having problems finding your posts, you can use the advanced search function button and type in your name.

Just trying to simplify the fix.
Old 08-20-09, 01:57 PM
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31 psi will start that engine. I suspect you have a code stored for an IGF and the problem isn't the pump pressure, but an electrical/electronic one. I would begin the fix by pulling the codes.

You can get a cheap beeper for a Ranger at most auto parts stores.
Old 08-20-09, 03:14 PM
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I'm sorry about that and Thanks!
Old 08-21-09, 05:45 PM
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The engine is not putting out any check engine codes, but I just found out that after I changed my fuel filter the pressure went up to 34-35 PSI. I also noticed some small particles and what appears to be water in the fuel after I emptied the fuel filter. Now I just need to find out a good way to clean the fuel tank. Hopefully that will take care of my stalling and starting problems.
Old 08-21-09, 10:34 PM
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Check the fuel volume, should probably be a liter in 30 seconds or something like it. A weak pump can deliver pressure after a bit but the volume wont be there.
Old 08-29-09, 09:00 PM
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Well I removed the fuel tank, cleaned it and installed a new fuel pump. Because I put in a new pump, I have not checked for volume, yet. Fuel pressure is over 30 PSI and it still has a hard time starting. What stops the fuel pump from running when you first turn the key to the on position? I noticed when I turn the key on, the pressure goes up to 40 PSI. The fuel pump does not stop running and the truck has a heck of a time starting. As soon as the pump stops when the key is on, the truck starts right away. The check engine light does not come on. I did notice that after the engine warms up and goes to idle, out of nowhere, the engine starts to fluctuate and goes over 1000 RPM from 600RPM. Then it settles back down and jumps again to a higher RPM. It does not have a steady idle. Suggestions? Thanks!
Old 08-30-09, 01:24 PM
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Perhaps a leaky fuel injector (if equipped)?
Old 09-19-09, 07:39 PM
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I am not sure about the fuel pump problem and don't know the size engine you have but I had an idle problem on my 4.0 that was caused by a missing vaccum cap at the vaccum port. It also caused it to be hard to start. Simple fix if a cap is missing or a broken vaccum line.
Old 08-06-14, 06:46 PM
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i have the 4.0 to and its doing the same thing. when the key is in the run position the fuel pump keeps running and wont shut off. i also hear something that sound like air blowing under the hood. i have check all the vacuum lines i could find and tried to feel around with my hand and can not find the leak. also when i get the fuel pump to shut off the is no air leak sound. any ideas?
Old 08-06-14, 08:08 PM
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That being said, after you turn key into ready position, or II, it'll prime fuel rail/injectors, for about 2 seconds, to have pressure build up in case you decide to turn key into position III, or start.
That's what you should hear. 2 sec, shut down.
ECM controls the pump. What exactly makes it run on your Ford/Mazda, that i do not know, but on Hondas and Toyotas of same years there is a main relay that does that.
Pump should not be running, unless engine runs. When engine runs, ECM calculates pump run based on need from engine. But say in case of accident and engine shut down or stall, pump should shut down instantly. It's basic hazard to have it run.
Old 08-07-14, 06:53 AM
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Hillbilly and Ukrbyk,
FYI this is a 5 years' old thread. I hope he's got it figured by now.
Be nice to know what the fix was actually.

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