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<\/a><\/p>\nExplanation:<\/em><\/p>\n The IDI fuel system is comprised of one (or two) fuel tanks, fuel pickups, a selector valve, a lift pump, a fuel filter\/water separator, injector pump, injector lines, and injectors.\u00a0 The lift pump sucks fuel from the tank, up the pickup, through fuel hose to the selector valve, and through more fuel lines up to the lift pump.\u00a0 Then the lift pump pushes the fuel to the Diesel fuel filter through metal lines on the front of the engine.\u00a0 The fuel is filtered here and then pushed into the Injector Pump inlet,\u00a0and the IP subsequently pressurizes and fuels the injectors<\/a>.<\/p>\n If there is a problem, a fuel system repair has occurred, there is a fuel leak, or a part has failed, your fuel system may have drained out.\u00a0 This is how you check to make sure you are getting fuel up to the filter.<\/p>\n On top of the Diesel fuel filter is a Schroeder valve.\u00a0 This valve serves two purposes:\u00a0 purge air in the fuel lines after a repair, and check to see if there is fuel or pressure in the system.\u00a0 The valve is no different than a valvestem on a car or bicycle tire.<\/p>\n <\/p>\n Preparation<\/em>:<\/p>\n Typically, you will need to purge the air out of your fuel lines if the following events had occurred:<\/p>\n Tools Necessary:<\/p>\n <\/p>\n How to purge air or check for fuel<\/em>:<\/p>\n Image of a generic filterhead from DieselStop, which shows a typical Schroeder Valve on the right.<\/p><\/div>\n Using the screwdriver (or any pointy object),\u00a0depress the center pin on the valve located on the top of the diesel filter housing.\u00a0 In vans, the filter head is located on the top of the engine on the driver’s side, and on the truck, it is located\u00a0near the passenger side valve cover.\u00a0 Have a friend crank over the engine, in 15-second-START and 2-minute-OFF intervals<\/strong>.\u00a0 Never crank an IDI for longer than 15-seconds at a time.<\/strong>\u00a0 Hold a cup underneath the depressed valve to catch any spraying fuel.\u00a0 I like to wear safety glasses, just in case a drop or two sprays out of control.\u00a0 For the most part, if there is fuel, it will lightly dribble out of the valve.<\/p>\n Once the fuel is flowing without bubbles or spurts, then most or all the air should be vacated from the system.\u00a0 With the fuel lines purged and filter full of fuel, you can move on to purging the air from the Injection System, detailed in this article<\/a>.\u00a0 At this point, this article is done, if you have fuel flowing.<\/p>\n <\/p>\n What if I don’t get any fuel out of the Schroeder Valve after plenty of cranking?<\/em><\/p>\n Remember, never crank the engine for longer than 15 seconds at a time.<\/p>\n If you have cranked the engine for a few minutes (not constantly) and you still do not see any fuel at the Schroeder Valve, you have a fuel system problem.\u00a0 Start with the simplest things first, and work your way to the hard stuff.<\/p>\n 1.) First off, put fuel in both your diesel tanks.\u00a0 Ford installed all fuel pickups to have these terrible plastic saucers in the tank that fall off.\u00a0 They are commonly referred to as the “cones of failure.”\u00a0 When these break, they don’t reach down into the last quarter of the tank, and even though your fuel gauge shows you have some fuel, anything under 1\/4 is effectively “empty.”\u00a0 So put a few gallons of fuel in BOTH tanks, bringing up your fuel level to something the pickups can reach. Why both tanks?\u00a0 Sometimes your fuel selector valve may be stuck on one side, thus only pulling fuel from one tank.\u00a0 If you have one tank full and one tank empty, and the valve is stuck on the empty tank, the gauge will still read as if it is pulling from the full tank.\u00a0 By putting fuel in both, you can at least get your IDI running, and then you can troubleshoot the valve later.\u00a0 Also, some selector valves are water tight, but not always air tight; this means when there is an empty tank, it might suck a little air thru the empty side which creates some air infiltration and weaker running engine.\u00a0 By leaving a gallon of fuel in there, it always keeps the empty side a little lubricated and properly sealed up.<\/p>\n 2.) Carefully inspect all your fuel hoses and lines up to the filter head.\u00a0 Look for tears or holes in the lines.\u00a0 You might see seepage or drips from hoses that have a tear or bad seal.\u00a0 A hole in a fuel line before the lift-pump will mean the pump will pull from the path of least resistance, and that usually means air is easier to pull than fuel in a tank.<\/p>\n 3.) Replace the Diesel Filter.\u00a0 When replacing the filter, always refill the darn thing with diesel, because it saves a lot of cranking.<\/p>\n 4.) Check if you have unclogged fuel lines.\u00a0 Knowing you have a full tank and undamaged hoses, disconnect the inlet hose on your lift-pump (location described in the next sub-section) and put a brake-line bleeder<\/a> on it. 5.) Check the efficacy of your lift-pump.\u00a0 On the passenger side of the IDI block is a s 6.) If all these have been tested and you still don’t get fuel to the Schroeder Valve, check the metal fuel line from the lift pump to the filter head.\u00a0 You can easily undo the ends and blow thru it.<\/p>\n 7.) This involves a lot more work, but you can try dropping the tank and inspecting the tank and its pickups.\u00a0 I have two articles explaining the drop process for the center<\/a> and rear tanks<\/a>.\u00a0 Sometimes the fuel pickup bibs on top of the tank can get weak seals, and those can introduce air into the system, like in the image to the right.<\/p>\n <\/p>\n Hopefully these steps have aided you in troubleshooting your fuel system.<\/p>\n Getting fuel to the Schroeder valve but the engine still doesn’t start?\u00a0 \u00a0Check out this follow-up article:<\/strong><\/p>\n\n
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\nTry pulling a vacuum.
\na.) If it doesn’t build pressure and no fuel arrives in the reservoir, then you have a rupture somewhere.\u00a0 Air is leaking into the system.
\nb.) If it doesn’t build pressure but fuel quickly enters the bleeder reservoir, then you are good to go; move on to the next sub-section.
\nc.) If it builds a vacuum and you don’t get any fuel, then you have a pinched or kinked line somewhere, or a clog in the fuel system or fuel pickup, or the selector valve is stuck in the middle.\u00a0 This is the worst of all scenarios because it requires a lot of inspecting and tearing down.<\/p>\n<\/a>mall pump that is driven by the camshaft.\u00a0 There is an inlet bib and outlet bib.\u00a0 Stick a meter-long section of hose on the outlet and put the end of the hose in a bucket.\u00a0 Crank over the engine.\u00a0 If you don’t get fuel in the bucket, then your pump is likely busted.\u00a0 Don’t fret.\u00a0 Replacing a bad lift pump is a pretty simple job and you don’t even have to drain the crankcase to accomplish it.\u00a0 Also, this might be a prudent time to replace the mechanical lift pump with a spiffy new Duralift 7-9psi or 9-11.5psi electronic pump (e-pump).\u00a0 The e-pump has many advantages over the lift pump, which I will detail in a future article.<\/p>\n