switching fuel tanks question
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From: Perry Georgia
switching fuel tanks question
My 1987 F250 with a 6.9 n/a pickup has developed a problem recently. I had a relay go out and didn't get any fuel from any tank. Replaced the relay for the electric fuel pump and problem fixed. Now When I go from the front tank to the rear tank, nothing. I installed a fuel pressure gage right before the fuel filter to check for any problems and discover I wasn't getting any fuel from the back tank. I replaced the FSV a few years ago and that fixed the same problem. This time I still have the problem after replacing the FSV. I thought I had a bad or wrong FSV but it's the exact same number and doing the same thing. Any ideas? Dash switch, wiring? Anything else to look at or for? I"ve replaced the rear tank about a year ago with a new tank and everything looked good.
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From: Perry Georgia
fuel gages read fine. Front gage reads what's in the tank and so does the back tank. I like going with the back tank because it's more accurate. The front tank is flakey. Reads full till you get to about 1/2 tank and goes fast to empty.
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how full is the rear tank? i've read plenty of threads here about the pickup tubes breaking off, leaving you "empty" if you're below about halfway. if its not full, top it off and try again.
or if you don't like that trick, test the FSV by running a hose from its rear tank inlet to a gascan and seeing if it sucks from there. also try to start a siphon from the rear tank's line to a gascan and see what you get. those simple tests will show you exactly where your problem is.
or if you don't like that trick, test the FSV by running a hose from its rear tank inlet to a gascan and seeing if it sucks from there. also try to start a siphon from the rear tank's line to a gascan and see what you get. those simple tests will show you exactly where your problem is.
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From: Perry Georgia
I had just filled the rear tank. I was looking at another problem, no fuel when I added the fuel pressure gage when I switched from the front to the back tank and found I had no pressure going to the fuel filter. I found I had a bad relay for the fuel pump which was my original problem. I replaced the back tank within the last year and don't like the thought of dropping the full tank. When I get time I"m going to put air to the feed tube to see if something might be blocking the back tank feed line.
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