Please help a new guy out, 6.9l issue.

5akman

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Hi,
My 19 yr old son just bought a one owner 1987 F250, 4sp, 2wd truck with 258K on the clock. The truck is in great shape for its age with zero body damage (no rust CA truck), good interior, new tires etc and he only paid 900.00 for it. The PO said that since new he has had the inj pump rebuilt 3 times, injectors 2 times and has replaced the block mounted lift pump 2 or 3 times. And, he removed the water separator years ago.

The truck has been sitting for 4-5 yrs but fired right up after putting new batteries, fuel filter and 5 gals of new fuel in it. It will not however stay running when you try to drive it even though it idles real smooth. When you try to drive it, it quickly dies as you shift into 2nd gear and he usually has enough speed to let the clutch out and the momentum bump starts it but it dies again. Fuel lines/pumps/return lines etc are all clean and dry showing no signs of leaking. The mating surface of the fuel filter did show some signs of rust however.....
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I used a fuel pressure gauge on it tonight and it runs up to 5 psi after about 10 seconds of cranking but the gauge pulses from about 3.5 - 5 psi while cranking. I then checked the lift pump flow and got about 4-5 oz in 10 seconds. I have done some reading on this site and in anticipation of possibly needing both a lift pump and water separator, ordered the Facet pump/filter last night.

While I wait for the pump, any other diagnostics I can do on this rig?
 

F350camper

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Congrats to your son for a great find, and great purchase. Sounds like you are well on your way to working out the kinks.

Lots of guys will be here soon with their ideas. One thing to check is, how full is the tank that you are running off of? The tank pickup tubes are known to break off, and you run out of fuel long before you think you would. So if you happen to be on the ragged edge of sucking air, it could be causing you issues.
 

icanfixall

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The atf in a clean fuel filter is a cheap easy way to clean up a sticky injection pump internals.You could just as easily fill the new filter with a quality fuel treatment and run till the treatment is in the injectors and pump.
 

Thewespaul

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And just as an FYI, that is the very best year for the 6.9, and some will say the best year of these IDIs, that truck is find.
 

IDIBRONCO

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It could be in the injectors or injector pump too. No offense to anyone, but there's only three places to get a good, quality injector pump. Justin at R&D IDI performance, Mel (Agnem on here) at Conestoga Diesel, and Russ (Typ4 on here). They all do sell good injectors too.
 
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