Ok guys my truck has started to do something wierd, when the truck sits in one spot for a minute or so the trucks idle will drop down to around 600 rpm and the truck shakes like mad !! I took it to autozon and had them scan the truck becuase the check engine light was on it said bank 1 and bank 2 lean, i swapped out the fuel filter, changed spark plugs, and changed the oil nothing helped !! any ideas why my truck does this? all help is appreciated.


JHF

 

Change both fuel injectors, they are clogged

 

BOTH fuel injectors??? I thought there were EIGHT fuel injectors!!

What year, how many miles, engine type, exact codes given, chipped, is the SES light still on, etc. etc.

BUT, assuming you are still getting an SES, it could be O2 sensors (front ones), could be you need to get an injector flush (all eight , this is done at a shop, not the bottle crap), clean the MAF sensors, or a host of other things. You are/were on the right track, provide some answers to the above questions, and maybe some one here can point you in a better direction before you continue to pour money in the truck.

BUT, if you are no longer getting an SES light for the lean conditions, you might want to look into replacing / cleaning the IAC valve, as this controls the idle.

 

Ok here goes to the questions sorry for the delayed reply.... Yes the SES light is on the error codes are Lean bank 1 and lean bank 2 i dont remember the exact numbers of the errors.... i have cleaned the maf, replaced the air filter, and so forth all the maintenance crap. The thing that blows my mind is the truck runs and drives fine but when i pull to a stop the idle drops to around 600 RPM and the truck shakes severly its startin to **** me off for sure its rather annoying.... The truck is a 1997 EB Expedition 5.4L 131K on the clock.

John

 

Well I would look at the IAC valve then. This usually gums up and can cause the conditions you speak of. Have you checked the hoses for vacuum leaks? (I doubt it would be one, but you never know.)

 

Wait, Wait.Are you saying the SES light is still on? If so, I would not jump on the IAC just yet, but I would check for vacuum leaks on the hoses. Are the O2's the original? If so you might need to replace them. It seems you really have "fixed" most everything that could cause a lean condition with the exception of O2, and vacuum leaks. So......

 

OK, these were most likely your codes P0171 and P0174. There is alot of good info here on things to check if you get those codes. I ran a searc in just this forum and found the following:


https://www.ford-trucks.com/forums/s...earchid=728496

Take a look at some of these, see what you have done, missed, etc. and go from there. It does seem that alot of people that get these codes had a vacuum leak on a hose.

 

Ive never changed the O2s in the truck so i dont know if they are original !! ok so what would be the procedure for checking vacuum leaks on the truck? I used to have an eclips GSX and when i tested for vacuum leaks on it i would pressurize the turbo inlet but i dont think i can do that on this motor any ideas where to begin? yes the SES light is still on.

John

 

We posted at the same time, see my post just above yours.

 

I have the same issue and read the threads. I replaced the pcv valve hose that everyone says is the #1 problem associated with this symptom. Is there another popular hose thats prone to failing and causing a vacumm leak?

 

I had the same problem, here's what I did and it worked.

A guy who lives across the street told me(he's a ford mech) change the air filter and hand clean out the throttle body and wipe down the air intake and run a bottle of high end injector cleaner and you should be good to go.

 

I found the problem, one of the right angle rubber hoses had completely dry rotted in half. i replaced this and the truck runs like a champ !! The SES light is still on though.

John

 

disconnect the battery for 10-15 min and it will reset it.

 

will do so !! Thanks for all your help !!

John

 

Which rubber hose was it?