bucking truck
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bucking truck
i recently ran my truck out of gas.since then, it runs rough and bucks like crazy.i've changed fuel filter,plugs,pcv valve,plug boots.should i try replacing COP's or try changing the screen on the fuel pump?
Fleet Mechanic
Joined: Aug 2008
Posts: 1,446
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From: NE Iowa JD Country
have you tried run the codes?
yes it could be the COP's...but it also might be a plugged injector?...concidering that it happened after running out of gas...I'd lean towards the injector...or as you mentioned the pick sock for the fuel pump.
for this pick up sock...try opening up the fuel line...by the fuel filter is fine. try back blowing air into the tank...30psi should be fine, wouldn't get carried away with too much air pressure.
that said it might be wise to check the fuel pressure and get another fuel filter too. Many times "if" there is sediment in the tank, a new filter will replug quickly.
the pressure readings will indicate if a new pump is needed
Elder User
Joined: Mar 2010
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First thing I'd check is fuel pressure. If that checks OK, I'd just turn the engine off, disconnect the battery for 15 min., then reconnect it. The engine leaned out big time as the fuel delivery gradually worked it's way towards -0-. Any number of lean or misfire signals could have been sent to the PCM. Most of those you've covered.
You mentioned changing the plugs. Anything but Motorcraft may cause rough idle. Even with Motorcraft plugs, it can take 2-3 drive cycles for the PCM to recognize the new parts. ( as might disconnecting the battery cause similar relearning curve.)
The leaned out situation may have called for a higher output from the COPS, but I doubt that would be a permanent situation, because of the short duration of the original problem.
Dave
You mentioned changing the plugs. Anything but Motorcraft may cause rough idle. Even with Motorcraft plugs, it can take 2-3 drive cycles for the PCM to recognize the new parts. ( as might disconnecting the battery cause similar relearning curve.)
The leaned out situation may have called for a higher output from the COPS, but I doubt that would be a permanent situation, because of the short duration of the original problem.
Dave
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Jun 23, 2011 01:03 PM
