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  #13  
Old 06-19-2010, 02:48 PM
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Re: Multiple Codes...could it be one problem??

PO171>>>System too lean (Bank 1).....A lean air/fuel mixture has been indicated by an abnormally rich correction factor.

So I happened to notice last night as I was chugging along in my jeep(lol) that my overhead display tells me that my avg. mpg is averaging 3-4!!!! Hmmm, maybe I just don't understand the way things work, but if my pump was bad and not sending enough fuel then wouldn't my gas mileage be HIGH since the system is not using as much gas??? OR as the above code indicates...."an abnormall rich correction factor"....hmmm, something seems suspicious to me in that statement....What sensor dictates how much fuel to send to the injectors?? Or what sensor is determining there is too much air and causing the "over correction". I guess that would explain the fuel consumption issue wouldn't it?? Maybe just my imagination, but yesterday when i got out of the jeep while it was still running, I could swear I smelt gas...didn't know really if it was coming from exhaust or up front somewhere(windy). Any ideas on this??? Ya, i'm grabbing at straws, hoping it's just some stupid little sensor and NOT my fuel pump!!!! haha. The test Monday will tell, but hoping for something to feel optomistic about~~
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  #14  
Old 06-19-2010, 05:46 PM
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Re: Multiple Codes...could it be one problem??

For the engine to run fine the injectors need a certain pressure to create the right spray pattern. If the pressure is too low the pattern is not ok and the fuel is not mixed well. So the PCM will put more fuel in to get the result (rpm increase) it needs. So this will result in a higher fuel consumption and if the fuel/air mixture is not well mixed it can be that unburned fuel enters the exhaust, what causes the smell.
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  #15  
Old 06-19-2010, 11:23 PM
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Re: Multiple Codes...could it be one problem??

Pre-cat O2 sensors dictate how much fuel is used/needed to get a 14.7/1 AFR.

But you have no O2 sensor codes???
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Old 06-21-2010, 09:45 AM
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Re: Multiple Codes...could it be one problem??

Headed to the mechanic here shortly to have some fuel pressure tests done. For the past couple days the jeep had only the 171 code. Now today we are back to misfires on 1,3,5,7 cylinders and the same system too lean in Bank one code.....171. Hmmm. They are all on the same side. does the fuel pump feed each side seperately?? What else would cause this all on the SAME SIDE of the engine?? any ideas?? I'll let ya all know what I find out from the shop today!
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Old 06-21-2010, 12:46 PM
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Re: Multiple Codes...could it be one problem??

The fuel is fed via an U-shaped feed line, which start on the right side close to the firewall (when seen in the direction of driving) and then turns left and goes to the left bank. You could have a look there to see if the tube doesn't have a knick or other damage, which could restrict the flow. There could be something sticking inside the tube as well, reducing the pressure and flow to the left bank.
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  #18  
Old 06-21-2010, 01:03 PM
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Re: Multiple Codes...could it be one problem??

Disregard my previous message. The fuel feed line is indeed an U-shaped line, but the fuel enters in the middle on the left bank side. So my story of obstruction of the line can not be the case.
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  #19  
Old 06-21-2010, 02:23 PM
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Re: Multiple Codes...could it be one problem??

Okay People.....the fuel pressure tested out to be fine. the coils are fine, the injectors are fine. took the O2 sensor at the left precat out thinking we could release back pressure......and would then figure the converter is bad. Well, that didn't work. My mechanic is totally stumped. I should explain that today i have codes for the 1,3,5,7 cylinders misfiring. However, his scanner indicated the misfire but it wasn't showing the specifics like he said it should (i'm assuming cylinder positions or whatever regarding the misfire) So, anyhow, he's stumped. He is now going to pull the plugs from the left side and do a compression test....he said even doing that doesn't make sense as all 4 plugs wouldn't go bad at the same time on one side of the jeep....or anything else realting to that one side all at once for that matter. He has ruled out the possibility of the computer being bad at this as well.

Soooooooooooooooooooooo does anyone have any further thoughts on this????
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Old 06-21-2010, 02:51 PM
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Re: Multiple Codes...could it be one problem??

The PCM recognizes a misfire by a small decrease in engine speed at the moment of the ignition at the respective cylinder, it doesn't necessarily mean that there is no combustion at all. Because you have messages that the fuel/air mixture is too lean, maybe a good idea to have the O2 sensors checked out. An other possibility could be a blockage in the left bank exhaust system.
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  #21  
Old 06-21-2010, 05:42 PM
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Re: Multiple Codes...could it be one problem??

Well, the day just keeps getting worse and the bill is adding up. Mechanic cannot get the coils out!!!!!! they are STUCK!!!! ERRRRR. forgot to mention earlier that there also are no vacuum leaks. So, the mystery continues!
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Old 07-19-2010, 06:53 AM
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Re: Multiple Codes...could it be one problem??

DebC68,
Did you get this problem solved? what was it? I'm having similar issues with a 6 cylinder right now, wondering what to look at next.
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  #23  
Old 07-19-2010, 04:18 PM
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Re: Multiple Codes...could it be one problem??

Do you have any coolant loss without external indications? Misfires can be caused by cylinder head gasket leaks. This engine can have problems with galvanic corrosion of the aluminium cylinder head at the places where the headgasket touches. The aluminium is being eaten away until it comes to a point that the gasket can not seal anymore. In that case you will most probably see air bubbles in the cooling system expansion tank when the engine is running.
See attached site for similar problem on Dodge 4.7 engine. http://www.denlorstools.com/autoblog...e-head-gasket/
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  #24  
Old 07-19-2010, 04:30 PM
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Re: Multiple Codes...could it be one problem??

Sounds like a vacuum leak, possibly from intake manifold to me, get some propane and go around the manifold to see if the engine runs better....also find a better mechanic. Shouldnt be stumped, and shouldve known replacing a fuel filter wouldnt have made a difference with those codes
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