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Discussion Starter · #1 ·
My 95 4.6 bird requires excessive cranking. It has been sitting for 2 years prior to last weekend. When you turn the key to the on position, I wait until I hear the fuel pump stop pumping, then I try to start the engine. It doesn't start in 3 seconds, so I let go of the key, let the fuel pump stop again, then the engine starts right up.

It seems as if the fuel is not maintaining pressure while sitting overnight. Is this a common fuel pump problem? Anything else I should check? I have not replaced the fuel filter but intend to...

Thanks
 

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3rd Gear Chirper
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Well, it could be leaking down from a number of places. There may be an injector that is not closing completely, the check valve in the fuel pump assembly could be bad, or the pressure regulator on the rail could be leaking- either to the fuel return line or the vacuum line.

Try taking the vacuum line off the regulator and smelling it. If it smells like fuel went down it then it's probably a bad regulator. Pressurize the fuel rail and put a gauge on the test port if one is available. Clamp off the feed line, and wait a few hours to see if it loses pressure. If not, then the fuel pump check valve is bad. If it does lose pressure, run the pump again and this time clamp off the return line. Let it sit, and if it loses pressure you have a leaky injector. If not, you have a bad regulator.
 

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Discussion Starter · #3 ·
Thank you so much hotbird! I will do as you instruct! Have a good weekend!
 

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1995 Ford Thunderbird SC 4.6L DOHC 524+RWHP
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I wouldn't chase after the fuel pressure bleeding down over night as the cause of the starting issue... I would expect any car to bleed pressure off in about an hour or two. It doesn't take much leakage anywhere to depressurize a solid(liquid) system, and after you turn the ignition on the system is up to pressure before the fuel pump kicks off. If your car has been sitting for a long time, I would go after: bad gas, plugs, clogged injectors, etc. Let us know what you find.

Mike
 

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The Parts Guy
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I agree that fuel pressure should bleed off overnight. However, the pump should be able to bring the system back up to pressure with just one prime. If it isn't doing that, you may have a weak pump.
 

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I agree that fuel pressure should bleed off overnight. However, the pump should be able to bring the system back up to pressure with just one prime. If it isn't doing that, you may have a weak pump.
agreed.
-Thomas
 

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3rd Gear Chirper
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Well yeah it may lose a good amount of pressure overnight, I should have said let it sit for a little bit instead of a couple hours, I didn't literally mean that, lol. A faulty component will lose pressure in probably a half hour or less...at least in my experience.

Now yall say that the pump should be able to bring a completely depressurized system up to pressure with just one prime? That's new to me, I thought it needed some residual pressure left in the system to make it in just one shot. Learn something new everyday :)
 

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WOT Junkie and avid corn burner
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My 95 4.6 bird requires excessive cranking. It has been sitting for 2 years prior to last weekend. When you turn the key to the on position, I wait until I hear the fuel pump stop pumping, then I try to start the engine. It doesn't start in 3 seconds, so I let go of the key, let the fuel pump stop again, then the engine starts right up.

It seems as if the fuel is not maintaining pressure while sitting overnight. Is this a common fuel pump problem? Anything else I should check? I have not replaced the fuel filter but intend to...

Thanks
I hate to tell ya, but this is normal... of course it's not going to hold full pressure over night, it's a return style fuel system. It will start up quicker if you start the engine while the pump is pumping. My car does this too and it does not have any problems at all.
 

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Discussion Starter · #9 ·
Well, NO, it's not normal. I've owned 3 94-96 Tbirds and 2 95 cougars. None of them did this except this one. If I turned the ignition switch on and cranked until the car starts, It's about 10 seconds. If I let the fuel pressure build up before I crank, then do it again after a 1 or 2 second crank, the cars starts right up.

Before sitting for 2 or 3 years, this car didn't do it either...
 

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well i would say fuel pump... most likely becuase it sat for so long and the gas turned to varnish and gumed it up, or the tank was empty and the pump rusted a little. i dont know if you did or not, but its alwase a good idea to put fuel stabalizer in the tank of a car thats gonna sit, and/or starting it up every now and then. i got a 90 3.8 sitting by the side of my house that i start, and let get to operating temp so the rings dont lock up. and i have added stabalizer.
 

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I am having the exact same issue with a '93 Crown Vic. The problem started before I replaced the fuel pump. The pump was replaced due to the steel lines going to the pump completely rusting through and leaking. I thought since I was replacing the pump, I'd kill two birds with one stone. But the problem is still there.


Jim
 

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Discussion Starter · #12 ·
Update-if anybody cares...

After running about 10 tanks of fuel through the system, I no longer have a problem. The car starts right up every time. Just thought I would let everybody know.
 
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