1987 Ford F150 shutting down

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WAFFALEE
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Engine Mechanical problem
1987 Ford F150 Two Wheel Drive Automatic 180000 miles

My vehicle shuts down after about 20 minutes of riding and if i let it sit for about 20 min it'll start and give me another 10-15 min before killing again. This is a continuous thing and i've replaced just about everything in the fuel system including switching valve because it has dual tanks. I' lost and local shops can't figure it out
Aug 26, 2010 at 10:16 AM
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JACOBANDNICKOLAS
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When it shuts down, have you checked for fuel pressure and spark to the engine?
Aug 26, 2010 at 2:50 PM
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JACOBANDNICKOLAS
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After thought... has anyone checked the ignition module in the distributor?
Aug 26, 2010 at 2:54 PM
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WAFFALEE
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no i havent checked the ignition module in the distributor so how do i check that and what am i looking for, and lastly what is the purpose of tat part? Thanks
Aug 29, 2010 at 4:18 AM
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JACOBANDNICKOLAS
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The module will need checked by a tech. It's purpose is to signal a spark for each cylender.

I have one other question. When it doesn't start, do you hear the fuel pump run for a second when you first turn the key?
Aug 30, 2010 at 12:54 PM
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WAFFALEE
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when the vehicle doesnt start i do hear the fuel pump so i will take the module off today to have it checked and will get back with you soon .thanks
Sep 1, 2010 at 12:10 AM
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JACOBANDNICKOLAS
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Let me know what you find.
Sep 1, 2010 at 4:06 AM
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WAFFALEE
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I had the module checked and all was good but i noticed that as soon as it shuts down if i spray fuel into the intake it'll start and burn the fuel that was just sprayed so would it be acceptable to say that something in the fuel process is overheating and shutting the system down? Its got dual tanks and the pumps were changed in both tanks and the pump on the fuel rail along with the filter so ???
Sep 2, 2010 at 5:19 AM
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JACOBANDNICKOLAS
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Yes. Have you checked fuel pump pressure?
Sep 2, 2010 at 6:40 AM
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WAFFALEE
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i will check pressure in the am but just curious at all times theres 2 fuel pumps operating one in either tank and on in the line is this correct? and if so why or what would lose pressure or heat up and how do you determine which pump is the culprit and what psi should i be looking for and from which pumps or is all the pumps gonna have the same pressure (inner tank and inline) thanks
Sep 2, 2010 at 3:47 PM
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JACOBANDNICKOLAS
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I believe there is one pump that changes when you switch tanks.
Sep 3, 2010 at 1:02 AM
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JACOBANDNICKOLAS
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There are low pressure pumps in the tanks but there is one high pressure pump on the frame. The high pressure pump should produce around 39psi.
Sep 3, 2010 at 1:56 AM
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JACOBANDNICKOLAS
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There are low pressure pumps in the tanks and a high pressure pump on the frame rail. THe pressure should be around 39psi
Sep 3, 2010 at 2:34 AM
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WAFFALEE
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ok i checked the pressure when the truck shut down and thats definitely the culprit so now i will check it before that pump on the rail be cause after it drops to about 5psi vise 43 psi.do you know what the pressure should be on the low pressure pump?
Sep 8, 2010 at 12:27 AM
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JACOBANDNICKOLAS
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Aprox 7 to 10
Sep 8, 2010 at 1:14 AM
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WAFFALEE
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Well im back again and still the same problem..The engine shut down after 25 minutes of running and i checked the fuel pressure after the last pump and all was good so i shot water from a hose pipe on the passenger side of engine and it immediately started and ran???? then shut down again after 30 min i wasn't shooting water any where around the ignition module??
Sep 28, 2010 at 2:28 PM
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JACOBANDNICKOLAS
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Wow! This is a tough one. I can't figure out what is on the passanger side of the engine that would cause it to run.
Oct 1, 2010 at 4:29 AM
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WAFFALEE
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i hate to be a bother but i can't figure it out either
Oct 3, 2010 at 9:44 AM
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JACOBANDNICKOLAS
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You are not a bother at all. I am going to ask another tech for his opinion. You will most likely get a response from him too, so don't be surprised.

Joe
Oct 3, 2010 at 2:49 PM
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RASMATAZ
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Next time it shuts down, immediately look for spark-if no spark test the distributor pick-up coil and the ignition coil and get back with the readings.

Its starts with outside fuel, runs till it burns off-check if the injectors are pulsing while cranking engine over-
Oct 3, 2010 at 11:59 PM
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WAFFALEE
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The distributor is new and the ignition module has not been replaced or taken off and physically checked but I pour cold water on it just to check it and I get same results which is nothing so should I actually take it off and physically check it? Also I hate to sound dumb but how do you tell if the injectors are pulsing while turning over ?
Oct 5, 2010 at 12:46 PM
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RASMATAZ
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Bring the ICM in and get it checked out
Oct 5, 2010 at 1:11 PM
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WAFFALEE
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i'll do that on tomorrow and get right back to you. Thanks
Oct 6, 2010 at 2:09 PM
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