Fuel problem???
Thread Starter
|
Freshman User
Joined: Mar 2004
Posts: 45
Likes: 0
From: Western NY
Fuel problem???
'86 F-250 4x4 with 6.9L. I've been having this problem for awhile and can't for the life of me figure it out. I go to start the truck. It fires right up, runs for a few seconds then quits. Then I have to crank it for half of forever to get it started again. It will idle fine for awhile, but then the idle becomes rough accompanied by blue smoke. When I step on the pedal, the RPM's increase and stay steady for a second, then start to hunt around. It sounds like it runs correctly for a little bit, then not, then right, then wrong, etc. When I let it return to idle, it runs right for awhile, then screws up and starts missing again. When I drive the truck, it runs fine under load and makes good power, but if I suddenly remove the load (take my foot off of it and throw the clutch in) it stalls and it's a real SOB to get it started again. Last time it took me several minutes to get it fired. I've already replaced the fuel line from the tank selector valve to the lift pump. I changed the filter today and noticed that there was only maybe an inch or 2 of fuel in it. SHouldn't it have been full?? Do I have an air leak somewhere I haven't found yet? Could it be the actual lift pump is bad??
Post Fiend
Joined: Nov 2004
Posts: 5,638
Likes: 1
From: Manitoba
Do you have any wet areas on the fuel return lines or the filter header. Air intrusion will give you those symptoms at start.
Take the Schrader valve core out and hook a hose and pressure guage to the outlet.........crank engine see what you get for pressure, should have 4-6 psi from a good lift pump.
Volume test same place hook a hose to it crank over the engine 10 seconds you should get 1/3 pint of fuel minimum or 1 pint at 675 rpm in 30 seconds... engine running
Important the fuel shutoff solenoid (FSS) wire on the IP should be disconnected if you do not want a start just cranking. Re connect FSS after test complete.
I would also check the connections on the new line for air leaks.
Take the Schrader valve core out and hook a hose and pressure guage to the outlet.........crank engine see what you get for pressure, should have 4-6 psi from a good lift pump.
Volume test same place hook a hose to it crank over the engine 10 seconds you should get 1/3 pint of fuel minimum or 1 pint at 675 rpm in 30 seconds... engine running
Important the fuel shutoff solenoid (FSS) wire on the IP should be disconnected if you do not want a start just cranking. Re connect FSS after test complete.
I would also check the connections on the new line for air leaks.
i ain't rite
Joined: Mar 2005
Posts: 65,447
Likes: 5,517
From: Marlboro Mental Hospital.
also check to see if the fuel bypass line fron injector returns to furl filter is still hooked up. if it is, block it off at the filter, and plug the line. this should cure the cold start problem.
