Have a 2000 mercury mountaineer that is crazy rich on idle,just dumping gas in the exhaust,fuel pressure is good,burning a ton of gas.live data is as follows
fuel system 1 CL fault(if I shut it off and restart it will go to OL fault)
Fuel system 2-na
calc load 33.3
ect 174
stft b1 -23.4
ltft b1 0.0
stft b2 42.2
ltft b2 0.0
engine rpm 856
veh speed 0
spark advance 18.5
IAT(F) 66
MAF 1.7
TPS 18.8
02SLOC B1S12_B2S12
02S B1 S1(V) 0.920
STFT S1 -23.4
02S B1 S2 0.000
STFT B1 S2 99.202S B2 S1 0.765
STFT B2 S1 42.2
02S B2 S2 0.910
STFT B2 S2 99.2OBD SUP OBD2
Any help would be very appreciated-Thanks

 

Have you monitored the B1 S1 and B2 S1 sensors with the engine up to temperature and running to see if they are behaving the way you would expect? Based on the fuel trims it seems the engine thinks bank 1 is running rich and bank 2 is running quite lean, or at least was when you took the snapshot. Since the LTFTs are both showing 0, was the engine recently started when this data was captured?

Does the engine seem to run fine otherwise? Do you happen to have a cold air intake or maybe a drop in reusable air filter?

-Rod

 

thanks for the reply,everything is stock on it,its a friends vehicle,we found some broken wires in the harness,repaired them,replaced the exhaust from the manifolds back 2 the muffler,the cats were rusted through,the wires to the oil sensor in the oil pan were burnt together where the cat had a hole in it,we just cut the wires off that so they were not shorted together,have not fixed that yet,not sure what that sensor actually does.when I got the live data my buddy had just came back from a ride,I went out and started it and plugged my scanner in and started recording so it was pretty much up to temp idleing in my driveway when I recorded the data.Seems to run fine just off from idle,even though it is eating gas like crazy all the time.

 

Did you install new cats when replacing the exhaust, and does the new exhaust still have all four of the oxygen sensors?

Since the engine seems to otherwise run fine, I'd probably start by cleaning the MAF sensor elements, then reset the KAM to see if that makes an improvement.

Does the exhaust smell as rich as the fuel economy might suggest?

-Rod

 

We pulled the complete exhaust off another 2000 mountaineer and installed from manifolds back,Changed MAF sensor off other one also,the other mountaineer ran fine but was wrecked in the rear.The exhaust is so rich on idle it burns your eyes.We were going to change the computer but it wont even start with that one so I assume it has to be vin matched.

 

Your assumption is correct, the anti-theft system is VIN-matched to the ECM. If you also swapped out the PATS module along with the ignition cylinder and key, you'd probably be able to get your Mountaineer started. But if you're not getting diagnostic codes, I doubt swapping the ECM will change anything.

With as rich as it sounds like it's running, have you tried pulling spark plugs to see if any in particular seem to indicate they are running very rich while others maybe look more normal? If you can identify a few cylinders that are really rich, then you can maybe start swapping plugs/wires/fuel injectors for those cylinders with others to see what item the condition follows.

If all spark plugs on one or both bank(s) look like they are running rich, then you can be pretty confident you need to focus on something that would be common to an entire bank of cylinders or both banks of cylinders.

-Rod

 

we have pulled the plugs a couple times,checked compression(which was good),whatever the problem is its affecting all cylinders,plugs are all black

 

Do you have a fuel pressure test gauge to check the pressure at the injector rail?

-Rod

 

Yes I have one,we did check it a while back and it was within spec with the chilton manual,will check it again tomorrow to verify its good.

 

where is the pats module located?We have changed everything,runs exactly the same,going to change the pcm,key,and pats and try it,luckily we have a complete parts vehicle 2 pull parts from.thanks

 

Does this have the old school style fuel pressure regulator with a diaphragm? If so, have you pulled the vacuum line to the regulator to see if there's fuel in it?

 

The PATS module will not effect the way the engine runs once started. It can keep the engine from starting, but it won't make any difference once running.

Now, if the goal is trying to change the PCM, which requires changing the PATS that is programmed to the PCM, that's a different story. The PATS module in your 2000 Mountaineer is located behind the passenger side airbag module.

-Rod

 

Mikeman this has the regulator on the pump,it has a new pump in it.shorod we are changing it so we can try the other computer,its pretty much all that's left to change.So you say behind the airbag module,do you mean behind the airbag itself?thanks

 

Just thinking out loud here and maybe this doesn't make sense or is even possible so feel free to tell me if I'm being stupid. With fuel trim on one side being positive and the other being negative, have the O2 sensor connectors been swapped from left to right side? I can't remember which model, but I know there's at least one out there that isn't Murphy-proofed to prevent cross-connection.

 

thanks for the help guys-pcm was the problem,runs brand new