Fuel Fuel Not Going Into Fuel Rails

Rid

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Sep 22, 2016
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I have a 94 gt 5.0 that will not crank . I have replaced the fuel pump and I know that is working correctly because it will pump fuel out of the fuel line where it meets the fuel rail but it seems like the fuel is not entering the fuel rail. I sprayed fuel directly into the throttle body and the car started so I'm sure the problem is at the fuel rail. Anyone have any ideas or suggestions please help! Thanks.
 
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jozsefsz

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Aug 11, 2013
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You'll want to check fuel pressure, just because the pump is capable of open-flow pumping doesn't mean it can build up enough fuel pressure to get the car started. Other things could be clogged / stuck / inoperative fuel injectors (lots of things could cause that but it's sometimes the distributor pickup) or a bad fuel pressure regulator (the fuel pressure check can help diagnose that) or bad fuel (if what you sprayed didn't come from the tank).

See this for comprehensive diagnostics:
http://www.stangnet.com/mustang-forums/threads/cranks-ok-but-no-start-checklist-for-fuel-injected-mustangs.787471/
 

Rid

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Sep 22, 2016
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well I test the fuel pressure it's only 15lbs. Does that mean the regulator is bad?
 

jozsefsz

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Aug 11, 2013
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If your reading was done properly (15lbs is the max pressure that the rail shows after turning the key several times to build up pressure) then the possibilities are fuel filter, fuel pump, pressure regulator, or a fuel injector stuck open (causes all the fuel to drain into a single port). It's supposed to reach ~39psi.
 

Rid

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Sep 22, 2016
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Well we just replaced the fuel pump with a new BBK pump and new fuel filter. So i guess it's down to the regulator or an injector.
 

jozsefsz

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Aug 11, 2013
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It's not impossible for a new pump to have problems unfortunately. If you pull the vacuum hose off of the regulator and find fuel then the regulator very well could have gone bad. The stuck open injector is easiest to test by pulling the rails out of the manifold and turning the key, and seeing if one shoots out fuel (it shouldn't until the car is cranked). Good luck.
 

Rid

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Sep 22, 2016
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Ok thanks I'll test these out. I'm really hoping it's not the pump don't want to have to drop the tank again
 

Rid

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Sep 22, 2016
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Well the regulator was bad had fuel in the hose replaced it and still nothing so going check the injectors.

The fuel pump is pumping but could it still possibly be bad? Once we replaced the regulator the fuel pressure went to 20lbs instead of 15lbs. Would this be caused by the injectors or something with pump
 

Rid

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Sep 22, 2016
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I know on the stock fuel pump you could hear the pump come on when the key was first turned on. Does that apply to all electric pumps? Should I be hearing the new when it comes on. Like I said I know it's pumping some but I don't know if it's doing
Enough.
 

jozsefsz

5 Year Member
Aug 11, 2013
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You should be able to hear it buzzing when you turn the key. If you can get a helper, you can definitely hear it if you get close to the tank and someone else turns the key. If it's pumping some but not powerfully (and very quietly), you might want to check that you're getting a full 12V to the pump. Could be a wiring / connector corrosion issue.
 

Rid

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Sep 22, 2016
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I have new pump that I'm going to try also going to test the voltage at the pump to be sure.
 

Rid

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Sep 22, 2016
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Checked the voltage at the pump it's only 8 checked it at the interia switch only 8 so I guess it's gotta be the CCRM is messed up? Any other suggestions of where I might need to look?