onephatz Posted April 9, 2005 Share Posted April 9, 2005 I wanted to see if anyone had tried puting the fuel pressure regualtor back by the pump and running a single line up to the fuel rail. or if you could tee the line up by the engine and run just one line to the fuel rail and the other to a fuel pressure regulator and returning in the return line? if this is just a bad idea lemme know jesse Quote Link to comment Share on other sites More sharing options...
GrayZee Posted April 9, 2005 Share Posted April 9, 2005 Interestng idea, but I don't think it would work. I keep thinking about how a air brake system in a semi trailer works.. When the driver presses the brake, it applies air pressure to all the brake drums (even ones that are 60ft away) in order for the brakes to release, the air has to be vented out. If the only release vent was at the brake pedal then there would be a delay in the brake release. So... big trucks have what's called a "quick release valve" mounted on each axle. Sort of like a relay for the directing of air pressure. This way the air does not have to travel all the way down the length of the truck to vent out. I imagine that it would cause similar problems for your fuel system. The reaction time would not be fast enough. It sounds like a good idea, but if it worked, I'm sure car manufacturers would have been doing that a long time ago. Let say that it cost Ford $2 to put a return line in every Tempo they ever made.. well that would have saved them millions and millions of dollars if that one part was not needed.. Obviously it is needed though. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted April 9, 2005 Share Posted April 9, 2005 some of the late model ford cars use a return-less system.there is a pressure sensor on the fuel rail and the fuel pump is pulse-width-modulated by the ecm.return at the tank might work but you might need a bleed valve at the front. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted April 9, 2005 Share Posted April 9, 2005 some of the late model ford cars use a return-less system.there is a pressure sensor on the fuel rail and the fuel pump is pulse-width-modulated by the ecm.return at the tank might work but you might need a bleed valve at the front. Never heard of that.. but I could see how that would work. That would be a complex ecu controlled system. Not worth the bother on a Z. Running a return line would be alot easier. Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted April 10, 2005 Share Posted April 10, 2005 ...The reaction time would not be fast enough... Bingo. Mash the throttle from idle to full song and the pressure drops quickly in the fuel rail. With the regulator right there on the rail and lots of high pressure fuel behind it it can quickly catch up and supply the needed volume. However, put the regulator back at the tank and it has to wait untill the pressure drop travels the whole length of the fuel line before it can react. The likely results would be an extremely lean condition leading to stalling before the regulator could catch up. The Ford one line system works because electrical impulses from the rail mounted sensor to the ECM, and then to the fuel pump, travel at the speed of light as opposed to the relative snails pace of a pressure drop in a liquid line. Quote Link to comment Share on other sites More sharing options...
auxilary Posted April 10, 2005 Share Posted April 10, 2005 no, really, returnless fuel systems do exist: my neon has a feed line to the fuel rail, and that's it. no return Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 10, 2005 Share Posted April 10, 2005 Most current toyotas or maybe all? use a returnless fuel line system. Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted April 10, 2005 Share Posted April 10, 2005 IIRC the new Corvette uses a returnless system, but some users modify it to have a return line. It is said to perform better with a return line than with returnless. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted April 10, 2005 Share Posted April 10, 2005 no, really, returnless fuel systems do exist: my neon has a feed line to the fuel rail, and that's it. no return I don't think anyone was ever denying that they existed, but if anyone is actually thinking of making a system like that in a old Z then maybe they should install ABS, traction control and air bags while they are at it... Personally I think just getting a decent wiper motor is challenge enough. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 10, 2005 Share Posted April 10, 2005 agreed, there doesn't seem to be any good reason to attempt to do this in an old Z, and it's not really 'cool' enough to do it just for the sake of being cool and different. What would be the benefit, and would it be worth the amount of trouble to get working? Quote Link to comment Share on other sites More sharing options...
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