Hi Everyone,
I've owned a 1986 F-250 6.9L diesel for a while now and haven't had many issues. However, during this past week, the truck died on me four times during my regular commute. I found myself accelerating up hills and around town just fine, only for the truck to lose power as I coast down the road. It completely dies and shuts off, all the lights and gauges continue to work, but the motor stalls out and the steering becomes extremely stiff. Then the truck will not turn over until I put starting fluid into it. Whenever this happens I noticed the tailpipe coughing up a lot of white smoke right before it stalls.
I had this issue in the past but was able to remedy it with a new injection pump. I've driven under 2000 miles since the new pump was installed, so I highly doubt that is the issue again. I suspected that I might have air leaking into the system at the return lines, so I replaced all of those today. Initially the truck was running smoother than before. I decided to rev up the engine, while at idle, and when I got to about 2500 RPMs the motor started kicking out a **** ton of white smoke then stalled again. I asked a friend about this and he suggested I look in my fuel filter (which I changed 3 weeks ago) and fuel tanks for any water. I dumped out the filter into a bottle then pumped a water bottle of fuel out from each tank and let them sit. After an hour, I didn't see the water and diesel separate in the bottles so I think my fuel is clean.
Unfortunately, my manual only recommends how to fix stalling after deceleration. But I believe I have an acceleration issue. Has anyone else experienced this before and can point me in the right direction?

 

put a fuel pressure gauge on the filter head and install a Clear line from the return to the filter head and make sure the Housing Pressure Regulator is not plugged.



IF your gauge reads good positive pressure and the clear hose test is good and the Housing Regulator is not plugged then you probably have a Bad IP.


BTW check your Air Cleaner too....

 

Thank you sir, I'll give that a shot.

 

As it turns out, my issue was actually one of the fuel lines right before the fuel water separator. There was usually enough pressure going to the primary filter, but under heavy acceleration that one rubber hose would suck in enough air to stall out the motor. The previous owner bypassed the fuel water separator, clearly trying to remedy this same issue. I changed out all the rubber lines and replaced the filter with a generic WIX separator and filter mounting bass. I haven't had any fuel issues since!