 914 1.8 fuel flow questions |
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| michaelmoo |
 Feb 10 2007, 03:59 AM
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#1
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Member  Group: Members Posts: 312 Joined: 21-May 04 From: Kennesaw, GA Member No.: 2,092  |
I need some one to explain something to me. I was looking at the diagram on Pelican and something didn’t seem right. If you follow the “Flow” arrows you don’t reduce the fuel pressure until after it goes to the injectors. Shouldn’t the fuel pressure regulator get the higher pressure fuel from the pump before the injectors? Maybe I don’t fully understand, but it just doesn’t make since to me.
I’m redoing all the fuel lines in my car (was carbs, but going back to FI) and need to know if the Pelican diagram is correct. Help please!!! Thanks, Mike Attached image(s) 
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Replies(1 - 4)
| type47 |
Feb 10 2007, 06:32 AM
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#2
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Viermeister Group: Members Posts: 4,254 Joined: 7-August 03 From: Vienna, VA Member No.: 994 Region Association: MidAtlantic Region |
i think the diagram is correct. the high pressure line ("D" for Druck on the fuel pump, i think the middle port) from the fuel pump goes to the injectors and then to the pressure regulator. the pressure regulator "bleeds off" the excess pressure back to the fuel tank (the return line)
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| Katmanken |
Feb 10 2007, 09:19 AM
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#3
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You haven't seen me if anybody asks... Group: Members Posts: 4,738 Joined: 14-June 03 From: USA Member No.: 819 Region Association: Upper MidWest |
That picture is right. The pressure regulator sets the pressure in the high pressure side and ALL the fuel injectors draw from that set pressure. Think of the pressure reguator as a valve that opens when the pressure is too high and closes when it drops and maintains the most even pressure it can for the injectors to draw from. After the pressure regluator, there is an open tube to the gas tank and pressure drops.
Do it backwards and each injector will be drawing gas at a different pressure, particularly the one that is farthest downstream. Ken |
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| Bleyseng |
Feb 10 2007, 09:54 AM
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#4
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Aircooled Baby! Group: Members Posts: 13,036 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
Yes, the straight out port is the return port/line. Just make sure the feed/druck line is hooked up correctly to the fuel injectors.
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| Dave_Darling |
Feb 10 2007, 10:41 AM
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#5
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914 Idiot Group: Members Posts: 15,204 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Think of the high-pressure loop of the fuel system as a garden hose with the water turned on. You can put your thumb over the end of the hose--what happens to the pressure inside of it? It goes up. Take your thumb away, and the pressure drops. The FPR is like your thumb, it serves as a way to plug the hose to raise the pressure, and then it opens up when the "correct" pressure has been reached.
So what it does is it keeps the part of the fuel system that is "upstream" of it at the specified pressure, not the part that is "downstream". --DD |
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