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1990 Coupe Deville
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22 Posts
Discussion Starter · #1 · (Edited)
1990 Deville How do I cap off return fuel line?

::edit:: I have to cap off the fuel return line, and I have no way to do this.. Is there anything I can pick up at pep-boys or autozone?? fuel pressure drops iwhen fuel pump shuts off, but works to spec when it's on and car runs fine, best mpg i've had... have to cap-off the return line to narrow it down between the pump or the regulator.. what can I use to cap the line off?

1990 Deville.
I have to turn the key twice to get enough fuel in the line to start the car, but I'm not stalling and it runs fine when it's on. recently installed fuel injectors, car was sitting about 6 months before the injector install. put in a junk yard distributor. and only 65k on the motor.
If I turn the key once to get the fuel in the lines I hear the pump and if I go to the release valve on the fuel rail and press it in a small amount of fuel sputters out with some air pressure that is in there. if I turn the key a few times to push some more fuel up there I can get a smooth stream but sometimes a little spitting from air pockets.
Also just put on a new fuel filter. the old one was pretty clogged when I got it off.
Don't know if I'm looking at a regulator issue or a pump?? Any ideas?
 

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Registered
1990 Coupe Deville
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22 Posts
Discussion Starter · #3 ·
ok thanks. Yea, I'll grab the fuel-pump test set autozone has on their loan-a-tool program. i have the 1990 Deville service manual from cadillac, but as thick as it is, it's not the most organized or descriptive service book i've seen.
 

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Registered
1990 Coupe Deville
Joined
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22 Posts
Discussion Starter · #4 · (Edited)
fuel pressure is at spec when running, drops immediately when off. priming the fuel without cranking gets 40psi for a second, drops immediately when pump stops.. Shop manual says to cap off the fuel return line and check pressure... so I stuck my finger in the return feed and the pressure stabilized.. so apparently it's the regulator

I'll grab one from rockauto.com and go from there

Thanks
 
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