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> 1973 1.7 fuel pressure issue
metalmorphosis
post Sep 1 2014, 07:43 PM
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First off like the title says I have a 73 1.7 car w the fuel injection still in place. The pump is 12-13 years old, I put it on when I bought the car as it didn't have the correct one on it when I bought it. Less than 2yrs ago I had the tank boiled out and lined by a local radiator shop and I replaced ALL lines w new stainless and rubber throughout.

So a couple weeks ago I tried to start my car and it wouldn't start. I had driven it just a few days earlier but now I've got nothing. After playing with some starter fluid I find it will run on that so I figure it has to be an issue w fuel pressure. So I assume maybe the fuel filter is somehow clogged. After replacing it still nothing so I borrow a friends pressure gauge and start lookin for pressure but still nothing.

So in the process of trying different things I find that if I pinch off the return line that y's off the engine supply line off the pump I have 70-80 lbs before the regulator. But when I unpinch that return line I have no pressure. I also noticed that w that line pinched I still had no pressure after the regulator so I took it out of the system and the car starts and runs just has too much pressure. But when that return line is unpinched it goes back to not having any fuel pressure.

Now that I've been studying all this stuff it doesn't make since to me how it builds any pressure to the fuel rails with the supply line splitting as soon as it comes outta the pump and returning to the tank. Although I assume it has to be plumbed correctly cause it has ran for just under 2 yrs like this. Hopefully I've described things good enough so what do y'all think?

Thanks Gabe
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Mike Bellis
post Sep 1 2014, 09:03 PM
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Sounds like you need a new pressure regulator.
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SLITS
post Sep 2 2014, 06:30 AM
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Supply line is not "Y'ed"; return line is. Line from Relief port on pump is "Y'ed" into the return line from the pressure regulator.

1.) Pressure regulator is bad

or

2.) Relief port check valve on pump is not holding
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JawjaPorsche
post Sep 2 2014, 09:51 AM
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Pelican has new ones:

http://www.pelicanparts.com/catalog/SuperC...L_pg2.htm#item3
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metalmorphosis
post Sep 2 2014, 07:13 PM
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I only have a few minutes tonight to add to this thread so hopefully tomorrow I'll have time to ask more questions. I discovered today that my assumptions were wrong about which way the fuel flows through the system, I thought it hit the regulator first then the rails but Im told that its the other way around, regulator last. So here is tonights main question if a fuel regulator fails does it fail open or closed? And if it does fail closed I would think you would see some pressure build in the rails, but with either of the 2 regs I have in place I see 0 pressure. Take them outta the system I have pressure.
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