I own a 1997 F150 XLT V-8 5.4L All the maint. is done and the oil gets changed at 3000-3200 miles no exception. I have 112000 miles on the truck. Recently I ran out of gas and the check engine light came on, it stayed on for the first tank but went off after I filled up the second time. It later came back on and teh engine started running rough at idle with a little loss of power in the top end. The engine will run fine on the highway. The computer says that the left and right bank are running lean. I have replaced the fuel preasure regulator and dropped the tank pulled the fuel pump cleaned the pickup screen. ( the pump was working, apparently fine).
I am at a loss and about to take it into the dealership $$$. Any suggestions before I do that.

Thanks for anything

Cam

 

i went through that last spring did you check injectors one or more could be pluged.

 

Check your injectors. Running the vehicle out of gas you could have sucked up sediment into the system. I pulled mine while doing the spark plugs and found several with crap on them so I cleaned. Also, you might want to change the fuel filter too.

Hope this helps.

Al

 

Running lean means two things. Low fuel pressure or more than likely a vacuum leak. After hunting and searching, I found the vacuum leak on my 5.4

Grab the PCV, follow the hard line back behind the engine, You will find on the VERY back a right angle boot that most dont even know exists. It rotts with oil vapor from the PCV. Its about the same as the one hooking to the PCV, but it has a 7/16 to 3/4 opening. Check that because it isn't a matter of if, but when it rotts according to the parts counter at my local dealer. He said the shop replaces those all the time on 97-99.

If that's not it, check all other lines and then check fuel pressure, Filter whatnot