Lean codes HELP!!!

[00explorersportlocked]

Ok. ..... I have a 2000 explorer 4.0 ohv. I'm getting the two notorious lean codes and am about ready to scream. I have done as follows. .. new upper and lower intake gaskets, new maf,new tps,new iac,new o2 sensors x3, new temp sensor, new ac temp sensor. I have also sprayed 4 cans of carb cleaner all over the engine. I can't find any vacuum leaks anywhere. I smoke tested the intake no smoke coming out anywhere. I'm lost I have no other ideas. my short term fuel trims are fluctuating from -1 to 3 but my long term stays at 25%. with that said. ... my cel isn't on but my scanner reads the codes and deleted them and re reads them fine. i tried to have new keys made and the locksmiths computer wouldn't connect with my pcm. any help wild be appreciated.

 

[2000StreetRod]

Have you measured the fuel pressure? It should be about 65 psi.

 

[00explorersportlocked]

Yes fuel pressure is at 68psi. I put a new fuel pump and filter in about a month ago. cleaned the tank completely and cleaned the lines unhooked of course with purple power and compressed air. replaced plugs and wires also.

 

[00explorersportlocked]

I can put premium gas in and it runs better. octane booster with premium and it runs even better. it seems to have an intermittent miss at idle. not very noticeable at all. seems to be every other or every couple full engine rotations only at idle. no other codes. I have unplugged o2s one at the time and I get a code. same with the maf and iac. plug em back up code gos away. the truck isn't running bad just has a little power loss sometimes and an occasional high idle sitting still. if I put regular fuel in it then is runs like crap. will die after acceleration sometimes and idle ruff.

 

[RandomNerd2000]

If your code reader is connecting with the PCM, the PCM is likely just fine. There a chance this could be a MAF problem?

 

[00explorersportlocked]

I just put a new maf in a few days ago

 

[00explorersportlocked]

List of new parts within the past month. ......I know is crazy but here goes. ...

New fuel pump, fuel filter, fuel pressure regulator.
Spark plugs,wires
Pcv valve and hose
Sensors- maf,iac,tps,temp,ac temp,all 3 o2s, egr pressure feedback
Gaskets- intake,fuel rail, plenum, injector o-rings,valve cover.

I have done as follows....
I built a machine to clean injectors with sea foam and compressed air@60psi. cleaned all 6.

I removed valve covers, intake, fuel rail,and plenum cleaned and replaced with new gaskets.

I built a smoke machine and smoked the intake through the brake booster hose. no leaks anywhere. I sprayed 4 cans of carb cleaner all over. no leaks. sprayed water all over. no leaks.

Fuel pressure is good (68psi), short term fuel trims are between -1% and 3%, long term fuel trim stays at 25%

O2 sensors all read good. I can spray carb cleaner in the intake and they instantly jump to .890 or so then back down.
If anyone wants to call me I can hook my scanner up and tell you all the live stream data. ask and I will post my number

 

[2000StreetRod]

You've made a very thorough attempt to resolve a stubborn problem! Is there a significant difference in your LTFTs at idle vs cruise? When you used your home built smoke machine did you disconnect a vacuum hose to see if smoke was forced out of the open port? When you replaced the upper and lower intake gaskets did you also replace the O ring that seals the EGR tube to the upper intake manifold?

 

[00explorersportlocked]

Yes sir. I taped off the throttle body so the smoke wouldn't get past the throttle body and I disconnected the vacuum line that runs around the back of the engine from the driver side over to the passenger side by the ac condenser until I seen smoke then connected it back. no smoke coming out anywhere. I even applied 10psi compressed air to the intake with the smoke and nothing.

The o ring came with the felpro gasket kit I purchased and I replaced it along with the gaskets. I put a little Vaseline on the o ring before inserting it into the plenum to stop it from getting damaged.

As for the ltfts.... stays the same no matter what. if i clear the codes it will drop to 24.3 for a few minutes then back to 25

 

[00explorersportlocked]

Sometimes I get a high idle in park. not all the time just occasional. I wish whatever it is would show is face so I can fix it and go back to riding trails.

 

[2000StreetRod]

My 2000 Sport with the SOHC V6 came with 4 O2 sensors (2 pre-cat and 2 post-cat).

I thought only the OHV V6 had the 3 O2 sensors configuration.

If you have a leak and the LTFTs don't change between idle and cruise then the leak is increasing with engine speed. Normally a leak will stay fairly constant so it has the most affect at idle and a decreasing affect as the engine speed increases. What color are the injectors? Do they resemble the orange ones shown below behind the fuel rail? The camera flash makes the two in front look more yellow than orange.

 

[00explorersportlocked]

My injectors are white and I have a flat aluminum fuel rail. they also have orings top and bottom. my exaust is different too. I have one o2 on the driver side then a small cat. one on the pass side then a small cat then two cats back to back then the third o2 and a single inlet muffler all factory. the 8th digit in vin is x

 

[2000StreetRod]

You have the OHV V6 and not the SOHC V6. I suggest that you change your first post in this thread accordingly. Hopefully, someone familiar with the OHV V6 will be able to help.

 

[00explorersportlocked]

Ok I changed it. are there any vacuum lines that go inside the fan box around where the heater core is?

 

[96eb96]

1) What is your BARO reading in Hg?
2) Did you answer the 2000StreetRods question about how LTFTs change when you go from idle to cruise? This is a big deal.