Help with Lean Code

[ronclark]

I am trying to track down the last bug i have in my 4.0 swap.
I put in two new O2's since the O2's on the Y-pipe did not plug in my harness.
I have checked for vacuum leaks nothing, i pretty much sprayed down everything with starter fluid twice.
New coolant temp sensor and air temp sensor.
i have also moved the o2's round and still 136.
it runs great i can a small smell of fuel right at the tail pipe.

any ideas?

 

[disciplerocks]

Have you checked/cleaned the MAF?

Did you reset you ecu after changing everything?

 

[ronclark]

Have you checked/cleaned the MAF?

Did you reset you ecu after changing everything?

yep i cleaned it. and i cleared the codes

 

[ronclark]

Bump.
Anyone else have any ideas?

 

[wahl_7s]

Did the cel come back after you cleared it? check the plugs see if it is truly lean could be a false reading drive for a while see if it clears itself.

 

[ronclark]

Did the cel come back after you cleared it? check the plugs see if it is truly lean could be a false reading drive for a while see if it clears itself.

Yep all codes have been cleared. i still get the codes on KOER.
well i decided to replace the injectors o-rings and the gasket on the fuel rail, the intake gasket i replaced when i did the swap.
well that did not fix it and gave me a new code grrr a 176.
Now what?

 

[chazzone]

I'd look for leaks in the exhaust system. If there is a leak ahead of the sensors, it'll show lean.

 

[bhawk]

You say you replaced the intake gasket. Is that the upper intake gasket where the upper intake meets the fuel rail, or the lower intake gasket where the lower intake meets the block and both heads.
The lower intake is where they leak, and spraying them down with whatever won't show the leak because the lower intake meets the heads UNDER the valve covers. If you haven't replaced the lower intake gasket, I would be doing that. You have to replace both valve cover gaskets when you do that job. I just replaced mine last week and the truck runs better than it ever has. No more high idle and smooth.

 

[ronclark]

You say you replaced the intake gasket. Is that the upper intake gasket where the upper intake meets the fuel rail, or the lower intake gasket where the lower intake meets the block and both heads.
The lower intake is where they leak, and spraying them down with whatever won't show the leak because the lower intake meets the heads UNDER the valve covers. If you haven't replaced the lower intake gasket, I would be doing that. You have to replace both valve cover gaskets when you do that job. I just replaced mine last week and the truck runs better than it ever has. No more high idle and smooth.

that looks like my next stop, what i don't get it has a great idle and power, driveably is not a problem.
I did some testing yesterday

MAF volts are all in range and it even swapped it to be sure.
Fuel Pressure is 40psi with key on, about 34psi running.
but my vacuum seem really low at a steady 13inchs

I am going to test my O2 volts today, but i am guessing its a lower intake gasket leak since i have with low vacuum

 

[bhawk]

I just replaced the lower intake last week and now our truck runs great. It actually ran pretty nice before I did the gaskets. No real driveability issues related to the intake leak, but we did get a higher idle than I wanted (about 1100-1000) at idle. Now she idles down to 650 when she is hot and that make is much easier to shift the old standard trans.
I believe that if the O2 sensors pick up lots of oxygen in the exhaust, (a lean condition), the computer will respond by adding fuel. That hurts the fuel mileage badly but the engine will actually seem to run not bad because the computer is doing it's best to compensate for the extra air.
Have you pulled your spark plugs to see if they are burning white??? If so, it's lean and I'd be doing the lower intake just to make sure.
There is one thing you could do instead of replacing the lower intake gaskets. Check the torque on the 8 bolts that hold the lower intake to the block. In my case, they were so loose I could turn each one out with one hand on the top of my rachet. Maybe I could have gotten away with just re-torquing the lower intake. Also be sure to follow the special technique for torquing that lower. It requires a special star pattern and doing the tightening in 3 separate sequences until you reach final torque specs. You must have a torque wrench, don't try without one.

 

[ttellup]

Im fighting the same codes. It started with a blown EGR tuge gasket caused by engine blow back form bad clogged converters. Killing my gas milage. So saturday I sprayed starter fluid on all the intake hoses and seals to find a leak. Just by dumb luck did i notice that the air cleaner was not tightened down to the intake pelum. Its only monday but no codes.

 

[ronclark]

Well i I replaced the lower intake gasket, which all the bolts were lose. rest the ECU.
My vac intake when up too 14" which still seems lows.
I still have a lean code on left side.
still cant locate the source of the leak/problem

 

[disciplerocks]

Vac on the intake should be 18-20 Hg.

 

[ronclark]

I wanted to give a update. I found the problem the O2 plug was wired wrong. Know everything seems to work.