no diesel flow??

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Feb 17, 2011 | 04:23 PM

4x4jimbo

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no diesel flow??

hi i just bought a 86 f250 4x4 6.9 diesel.it runs on ether for about 2 sec, but i seem to be not getting fuel running through the lines.i pushed the small valve stem on the fuel filter and it pissed air .i have never delt with this particular truck,were do i start?do these lines need to be bled?is this just a fuel pump problem?i also need to kno if there is a pumps in the tank?.if possible could someone direct me to a fuel line diagram or a manual??

thanks in advance ,jimbo

Feb 17, 2011 | 04:58 PM

Franklin2

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From: Virginia

No pumps in the tanks. How much fuel is showing on the fuel gauge(if it works). These trucks are famous for the plastic pickup piece in the tanks breaking off, and it won't pickup fuel if it's around 1/4 tank.

I would eliminate the tank system for troublshooting purposes, and take a rubber line and hook it to the fuel pump inlet, and drop it down in a bucket of diesel and see if it will pick the fuel up out of the bucket.

Feb 17, 2011 | 05:02 PM

IDIDieselJohn

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From: Ottawa, Ontario

Post this in the Pre PowerStroke forum, you'll get tons of help there.

These old Diesels have Mechanical fuel pumps like the old carburetor gas engines that mounts to the engine block, passenger side front of the block just below the vacuum pump.

If you aren't getting any fuel to the valve, either the fuel pump it's self is bad or how much fuel are in the tank?

If it's below 1/4 try filling it up over 1/2 mark, very common for the plastic pick up tube breaks off inside the tank at the 1/4 mark, so you run out of fuel at 1/4.

Feb 17, 2011 | 05:36 PM

4x4jimbo

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thanks guys. the bucket trick sounds like a good idea. ,the guy i bought it from was taking parts off it .i beleive there is saposed to be a water separator ,drivers side under the hood.i found that the fuel line wasnt even connected as if a after market separator was removed .i attached the line back .still getting vapor lock in the tank and air pissing from the valve on the filter?. i will agree there may be no diesel in it and im causing my own dilema.the guage i doubt works.i will have to get back to you guys tomorow seeing as i have no ride to get diesel

thanks jimbo

Feb 17, 2011 | 06:22 PM

IDIDieselJohn

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From: Ottawa, Ontario

Don't reconnect that water seperator! Those are to well known for leaking air into the fuel system and causing to loose prime.

Just use 7.3 style fuel filters with a little drain plug under them to drain the water.

Feb 17, 2011 | 07:01 PM

4x4jimbo

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my old man taught me to put rubbing alchohol in the diesel to get rid of water .it works great!. the water separtor is missing ,but thanks now ill just buy a filter instead .good trick man.

thank jimbo

Feb 17, 2011 | 07:29 PM

iron1951

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Joined: Oct 2006

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From: Welland, On

If you use the gas can full of diesel (I think this is a good place to start), you might want to use a clear hose to see if the fuel pump is picking up. Once you get diesel to squirt out the small valve stem, try starting the truck. If it does not start, you may need to bleed the injectors too. While doing all this, don't run the starter too long at one time. You can cook it and have to replace it. I did.

Since this is 6.9 engine problem, you might want to visit Pre-Power Stroke Diesel (7.3L IDI & 6.9L) forum, these members are great with the engines. I visit both forums depending on what area my problem is. One trick I learned from the 6.9 forum, is to replace the line from the fuel pump to the injector pump with clear line, for a while, to see if air is sneaking into the system. Another place to place a clear line is the return line from the injector pump back to the fuel filter.