bank 1 lean again

[pickupman6]

Ok 2000 xls 4.0 ohv every year when it starts getting cold the check engine light comes on and says bank 1 lean. What I have done so far is:
Checked fuel pressure 61 psi
Swapped injectors from bank on to bank two, no change
Did same with plugs knew that wasn't it but figures someone on her would tell me to do it
New o2 sensors
New intake gasket
Checked for vacuum leaks with propane and brake cleaner
Cleaned maf and iacv just cuz
New fuel pump and filter

I've had this problem the last 4 years and no one has been able to figure it out, once spring rolls around and it starts to warm up the problem is gone. It still runs great for 300k miles, 165psi across all cyl give or take about 5 doesn't burn or drip a drop of oil. I have been searching this forum and trs ever since this problem arose 4 years ago. No ones advice has solved my problem yet. Not even the dealership. The next thing I'm going to try is the ecu unless some one else has some ideas. Thanks.

 

[LONO100]

did you check that little rubber elbow hose next to the oil cap? it might be cracked on the underside where you cant see or test with propane. that was my problem, and im glad i found it because i was about to change my manifold gaskets until i found it.

 

[swshawaii]

Linked again. No PCV elbow on the 4.0 OHV. (SOHC Only)

http://www.explorerforum.com/forums/showthread.php?t=314670

 

[pickupman6]

I have an ohv but thanks anyways.

 

[Dono]

Wow, for what its worth, you have done everything I would have tried. I got nuthin but moral support for you. That and subscribing to see what the solution is.

What could cause too much air getting in to bank 1 only?

It can't be a fuel delivery issue. Pressures good, and you have swapped injectors around. Its not a bad o2 sensor.

Hows the idle? Is that the only code that comes up? Any pending codes? It just seems odd that only 1 bank goes lean.
Could a exhaust leak cause this? I doubt it. Exhaust gas leaving pressurizes the exhaust manifold, not sucking air. I got nuthin.

 

[pickupman6]

Idle is fine, it runs fine even at wot going up a hill. There is no exhaust leak evcept for a pin hole in the bottom of the muffler. I'm stumped. Got 3 dealerships stumped. I'm still getting 20 mpg combined which is close to the 22 I get in the summer, but all my cars have went down so I figure that to be the fuel. Oh and no that is the only code I'm getting. Thanks for the support.

 

[pickupman6]

Nobody else has any ideas?
Well I have another question. Is it normal for the ac compressor to kick on every 20 seconds stay on for about 10 seconds then go off. It does it all the time unles I actually have the ac on. Then it stays on for like a minute and cuts off for maybe another minute. It real annoyin listening to it in the am when its warming up. And it can't be good for it. Its done it ever since I've had it. I checked the freon a few years ago and it was in the green on my guages, but I loaned them to a friend who moved without ever giving them back so now I can't check it to make sure its still good but it still blows ice cold air in 100* plus weather so I'm assuming its fine. Thanks

 

[herebyproxy]

Air coming on

When the air control is in the windshield (defrost) mode the air conditioner comes on to remove the moisture from the air to the windshield. It also cuts in and out frequently. Just so ya know.....

 

[pickupman6]

Ok thanks that makes sense but I think it does it even when switched completely off. I could be wrong ill check when my wife gets home. I'm about to retire this thing as a dd and get a crv.