P0174 - Jeep Garage - Jeep Forum

Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WJ > Troubleshooting/Problems

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 11-15-2015, 07:03 AM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,434
Thanks: 19
Thanked 388 Times in 375 Posts
Rep Power: 529633
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
P0174

So after many problem free kmīs, yesterday i started the engine after being hot and standing for some 10 minutes. It started after a hesitation, but shut down immediately. Tried to start several times, but same result. No codes set. Was first thinking about the crank position sensor, but since it started, even for a short time, i discarded this option (at least for now). Listened for the noise of the fuel pump, but couldnīt hear a thing.
Later that day went back and it started, but was running rough for a while. Went home running normally, but halfway the check engine light came on. Checked the code with the keydance and it showed P0174: system too lean bank 2. Had a visitor over, so couldnīt look further into it.
This morning it started seemingly normal, eventhough the idle is not as smooth as it used to be. Went for some shopping closeby and after my return, put the scanner on it. O2 sensors 1-1 and 2-1 working normally, changing quickly from 0.2 to 0.8 back and forth. STFT (short term fuel trim) normal as well, going from -2 to +3. MAP seemingly normal, but when checking the LTFT (long term fuel trim), it came up with +25 at idle and +30 during driving. This means that the PCM is (trying) to add more fuel to the basic fuel schedule by increasing the injector pulse. From this new schedule (basic schedule + the compensation as shown by the LTFT), it was still doing its normal duty in respect to the STFT, fine trimming the fuel injector pulse to reach the best possible fuel mixture.
So this all leads me to believe that i have a too low fuel pressure. When driving faster and more fuel is needed, the mixture becomes too lean and the P0174 is set. (max compensation is reached, but with low fuel pressure, simply not enough fuel will be injected) So now i will look for a new fuel filter/pressure regulator and a new fuel pump cartidge.

__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 11-17-2015, 03:19 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,434
Thanks: 19
Thanked 388 Times in 375 Posts
Rep Power: 529633
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: P0174

Measured the fuel pressure today at the fuel rail; only 25 psi after several times priming (so half of the normal 49.5 psi). Removed the fuel feed line from the pump to the filter and measured the pressure directly on the pump; still 25 psi. So or the pump is bad, or there is a heavy fuel leak inside the fuel pump module. Started this afternoon with the preparations to lower the tank, hopefully will have more time tomorrow to get it lowered and have a look at the fuel pump module. Since my fuel level gauge is misreading, i can use this opportunity to bend the float arm a bit and see if that helps.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #3  
Old 11-19-2015, 07:47 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,434
Thanks: 19
Thanked 388 Times in 375 Posts
Rep Power: 529633
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: P0174

So since iīm not sure if any refill fuel pump will fit the Bosch pump module, i decided to buy a complete new pump module from Rockauto and a new fuel filter/regulator. Now waiting until the stuff will come in, which can take a few weeks.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #4  
Old 12-02-2015, 10:51 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,434
Thanks: 19
Thanked 388 Times in 375 Posts
Rep Power: 529633
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: P0174

Update: just installed the new fuel pump module and filter/regulator last Monday and its all running smooth again.
The only thing i hoped for, that the fuel quantity indication would return to normal with the new float assy, didnīt work out. With a full tank, the pointer on the instrument panel almost indicates 1/4 more then full. Almost the same as with the old float assy. With empty tank the resistance is around 272 Ohms and with full tank around 23 Ohms, which is ok according to the manual. This signal goes to the PCM and that one will send the signal via the PCI data bus to the instrument panel. With full tank the resistance should be higher then it is now, so thinking about installing a potentiometer in line with the level sensor wire, so that i can trim the level to full indication mark with a full tank. Not sure if i can find a potmeter in the range i will need, otherwise it will become experimenting with several fixed resistors until the right level is reached. Anybody already experimented with this?
Iīm aware that eventual bending the float arm could do the same, however i wonder if the empty reading will be reached then. Any experiences from others on this are welcome.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Codes P0171 and P0174 honda_fox3 Troubleshooting/Problems 7 07-24-2012 06:27 PM
Hunting down a P0174 problem tcolombo@cox.net Troubleshooting/Problems 5 08-25-2011 03:12 AM
P0174 Code?!? Jay Grooms Grand Cherokee - WK 7 05-22-2011 09:09 PM
p0174 A lean air/fuel mixture has been indicated ?? LimitedStyleJeep Troubleshooting/Problems 5 03-19-2011 11:18 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 02:02 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by FCA US LLC. Chrysler, Dodge, Jeep, Ram, Mopar and SRT are registered trademarks of FCA US LLC.