rough idle and lean code

green250 · #1 (**permalink**) 02-11-2008, 07:55 PM

I have a 2000 f250 superduty 4x4 5.4 liter.At idle it runs rough and misses.I am throwing a system lean bank 1 code.The rpms fluctuate up and down.While driving it still has a slight hesitstion and power is down with poor gas mileage.I have changed all fuel injectors,cleaned maf,replaced pcv and checked hose for crack/leak.I Also replaced the fuel presure regulator.Fuel pressure is about 38# not running.The coils have been replaced with accels about 7 months ago.just changed the plugs about 2 months ago but going to do it again.Any advice anyone has will be greatly appreciated.Ive already done searches and havent found anything to cure my truck yet.Thanks in advance to any suggestions.

Fordfreak_24 · #2 (**permalink**) 02-12-2008, 12:06 AM

my truck did something similar. there is a plug on the bottom of air filter housing. mine had poped off and was sucking in unmetered air. i had to permitex mine on to get it to stay. that might be something that you'll want to check. good luck

green250 · #3 (**permalink**) 02-12-2008, 04:57 AM

thanks,i looked and everything is ok with the air filter.

wilkinda · #4 (**permalink**) 02-17-2008, 10:20 PM

Mine did the same thing and it was the PCV on the right bank. Changed it out and the problem went away...

LxMan1 · #5 (**permalink**) 02-17-2008, 11:31 PM

Check the PCV hose elbows. Especially the one connected to the rear of the intake manifold.

FatDutchMn · #6 (**permalink**) 03-11-2008, 10:47 PM

Quote:

Originally Posted by LxMan1

Check the PCV hose elbows. Especially the one connected to the rear of the intake manifold.

Will this rough idle from the PCV have an effect on gas mileage?

projectSHO89 · #7 (**permalink**) 03-12-2008, 11:35 AM

Quote:

Originally Posted by FatDutchMn

Will this rough idle from the PCV have an effect on gas mileage?

If you have a vacuum leak, one of the most common symptoms is a rough idle (if the leak is large enough).

Steve