ok, check engine light is on. when I idle it stutters and the whole truck shakes but its not loud, then its fine when I drive off. Throws 2 codes saying lean. It died in an intersection today, I was ready to burn her down. anyone know whats up before I lose my *** at the ford garage??

 

i hate to say it but sometimes its no use messing around, go to the mechanic and get her checked out.
Sucks, but sometimes its the best thing to do for your rig instead of messing with stuff.

I have no clue what it could be, but if i had to guess, probably electrical/ computer issue?(Electronic Fuel Injection screw up)

 

Thats my guess too man, Ill prolly just have to bite the bullet and go there. thanx man

 

Check for vacuum leaks.

 

X2

 

noted, thanx!

 

Vacuum leaks.
Start with having a good thorough look at the air intake. Look for anything obviously loose or hanging off, unplugged. Make sure the IAC valve is on tight. Even a bad gasket on the IAC valve could cause this. Could go as deep as bad intake manifold gaskets or something else.
What codes are you getting specifically?

 

cant remember the code numbers, just threw 2 and they both said running lean.

 

Have you had a good look over the engine compartment and intake yet?

 

not as of yet, I looked it over good when I did my bodylift but I may have missed something

 

I would look at all vaccum lines first, including PCV, etc. They are hard to get to and see, the way it's Y'ed between the firewall.

I replaced the intake seals on my 99 Exp 4.0 SOHC. Wasn't too bad, but I like wrenching. A bit too much sitting in the engine compartment bent over for my liking. When you get the lower off, you'll see the carbon witness marks on the aluminum. Clean that surface to "bright", clean all the mating surface and install new seals. I want to say the parts were only ~$30 or so.

Mine were leaking so bad I could put my body weight on the top of the intake and rock back and forth, making the whistling sound change tone (engine idling, of course). Some pretty rock-bottom crude troubleshooting, but it confirmed the problem. I also used my body weight again when I was tightening them up. Go over them several times and don't let the creaking plastic sounds worry you. I literally watched the lower mating surface squash the seals with a mirror and flashlight as I drew them together and tightened all those bolts. When there was no air gap, I called it good.

 

I hate to keep repeating this but take a look at the PCV elbow that is located under the top radiator hose. It is connected to a plastic tube that comes from the back and ties into the throttle body. These rubber 90 degree elbows are known to deteriorate and cause the exact problem you are experiencing.

 

i threw two codes that said running lean too but also said the 02 sensor so check those too. my truck was idling rough and smoking.

 

what are the codes? I'm assuming P0171/P0174 that's lean on bank 1 and bank 2. Vacuum leaks cause this problem. check all elbows for dry rotted hoses or oil residue on hoses.

o2 sensors will read lean if there is extra air in the mixture and thus it's not the o2 sensor, but a vacuum leak.

 

Bad O2 sensors are rarely the cause of a lean code. They're expensive to replace and typically a shot in the dark. I had a lean code a while back, turned out to simply be a dirty air filter. Go all through the air intake looking for leaks or gunky deposits. Also check out the throttle body and clean if necessary. That throttle plate can get a lot of buildup on it and cause a rough idle.

 

went to ford and told thema bout it and they said vaccum leak or a leak in my intake, Ill run it through diagnostic next week if I cant find anything. Ill check the elbows out and see. Thanx for the input guys