2001 Expedition, dumping fuel, missing - no codes

[domslivin]

I have a 2001 Ford Expedition with 119,000 miles on it. I noticed a small what feels like a misfire at idle, fuel smell when it's cold, and big clouds of blueish colored smoke at cold starts. So I took it to Mike Naughton Ford and they said it was a fowled plug. $512 later, the plugs and boots were replaced and the problem still exists. I took back to them and they said they did notice fuel dumping out the exhaust at cold start, but the computer and diagnostics showed everything was within specs and sent me away. I replaced all 8 injectors, and cleaned the MAF sensor, checked all the vacum lines and still no change. So I took it to a small local shop who was willing to spend more time diagnosing things. The god a P0172 System to Rich Bank One The long term fuel trim on B1 is 10.15% on B2 - 4.68% Short Term fuel trim switching + ___ - 1.5%. They tested Oxygen sensors, voltages were good and switching fine, two compression tests and all 8 were ok and they determined it may be a leaking injector. I replaced all the fuel injectors before I took it into the shop so I was pretty sure that wasn't the problem but let them do their testing anyways. No leaks were found, the fuel pressure KOEO is 40psi., pressurized rails multiple times, no drips or leaks. System held 20psi. over night. In the end they said they agreed that something was definately wrong but were unable to determine what and sent me home $282 later with no fix in site. The only thing they could tell me is that it would need to fail before they could figure out what was causing the problem. I also replaced the PCM, IAC Valve, and had a leak down test done. The leak down test showed everything as good, and they also did a compression test that showed all the cylinders between 160 and 165. I also had the temperature sensor checked with an ohms meter and it showed it was working properly as well. There is still a misfire and it's still dumping fuel! The computer does not throw any error codes, no check engine light, and the temp guage seems pretty accurate as the vehicle warms up. I have a warranty on the vehicle, but if nobody can figure out whats wrong or admit there is a problem I can't keep throwing money down the drain for diagnostics. If you have any advice I would greatly appreciate it.

 

[stamp11127]

Which plug was fouled? And what type of fouling? If the injectors are leaking you would see the oil level rise over time since the gas would run past the rings.
In order to make it into the exhaust system, you would probably need a dead cylinder or one that isn't firing. A plug check would show if it is not firing - soaked in gas compared to the others.
The blueish smoke is oil that has slipped past the oil seals on the valves. Normal for engines as they wear. Once it starts getting heavy then you do a valve job.

 

[toms89]

Compression test gives you cylinder psi reading per cylinder such as 160. This differs from leak down test.

Leak down test tells you percentage of leak down per cylinder such as 5%. It can be more revealing telling you exactly where the "leak" is. Typically its the rings and you will hear the air leaking into the block itself via the oil fill cap. If you hear it leak into the intake you know you have a leaky intake valve, exhaust you have a leaky exhaust valve.


Positive fuel trim indicates the O2 sensor is reading lean yet you are getting bank 1 too rich cel !? Misfire can cause lean O2 reading but rich condition as it passes unburned O2 to the exhaust. It sounds as if you checked for vacuum leaks via hoses but you may consider checking for an intake manifold or plenum leak. I would focus on bank 1 (passenger side). Did you check for exhaust leaks ahead of the O2 sensors? They can also cause lean O2 readings.

Some other possibility's assuming all the spark plugs, cops, O2 sensors, injectors are good may be the wiring, connectors or even drivers for cops.

 

[domslivin]

That's just it, I have no way of knowing which plug is fowling because the computer is not showing any issues or throwing any codes now. They did the leak down test and said it was fine, but also performed a compression test and that's what the numbers were I put in the post, sorry didn't mean to confuse the two. When they did the leak down they pulled the plugs and said they all looked fine. I have not noticed any exhaust leaks, never hear any sputtering or anything anywhere. I agree its a possibility of a short in the wiring somewhere but it seems that no shop wants to actually help me, all they offer to do is hook it up to the computer, which isn't going to tell them anything because it's not seeing any issues. As I mentioned I replaced the PCM to eliminate the drivers being the issue and still no changes.

 

[domslivin]

Well I traded in my Expedition today on a new vehicle so I guess this thread can be deleted now, I just wasn't sure how. Thanks everyone for your advice!