57fan Posted October 4, 2011 Share Posted October 4, 2011 My 06 fusion has had a check engine light (MIL) 3 times this past week. it is for codes P-0171 and P-0174. Bank 1 lean and bank 2 lean. The problem is intermittent since I clear the code and it comes back a few days later. Yesterday I went to start the car and as fast as it started it died and set the same 2 codes again. The car seems to run great otherwise but I cannot find the cause. I have looked for an vacuum leak and found none. No signs of issues anywhere. I cleaned the MAF with cleaner and this has not solved the problem yet. So is anyone out there had this issue and if so what was the cause / fix? thanks for the help guys.. 0 Quote Link to comment Share on other sites More sharing options...
akirby Posted October 4, 2011 Share Posted October 4, 2011 My 06 fusion has had a check engine light (MIL) 3 times this past week. it is for codes P-0171 and P-0174. Bank 1 lean and bank 2 lean. The problem is intermittent since I clear the code and it comes back a few days later. Yesterday I went to start the car and as fast as it started it died and set the same 2 codes again. The car seems to run great otherwise but I cannot find the cause. I have looked for an vacuum leak and found none. No signs of issues anywhere. I cleaned the MAF with cleaner and this has not solved the problem yet. So is anyone out there had this issue and if so what was the cause / fix? thanks for the help guys.. Did you use carb cleaner to find a vacuum leak? Did you check for intake leaks? 0 Quote Link to comment Share on other sites More sharing options...
FusionDiffusion Posted October 5, 2011 Share Posted October 5, 2011 Most common cause is vacuum leaks. If you didn't see anything obvious with the hoses, you might have a leak around the intake manifold. As suggested, use carb cleaner or propane to try and find the leak. You cleaned the MAF which is another possible cause. Finally a lack of fuel pressure from a dirty fuel filter or a bad pump can cause an issue. Both are in the fuel tank as a combined assembly. 0 Quote Link to comment Share on other sites More sharing options...
57fan Posted October 12, 2011 Author Share Posted October 12, 2011 ok so here is the latest. I swapped the MAF with a known good sensor. Code's still came back. Checked for vacuum leaks with propane and found none. I checked the fuel pressure with a mechanical gauge. Reading 38 lbs at idle at WOT (no load). Unable to test fuel pressure under acceleration today. Ford states fuel pressure range from 48-79 psi. unfortunately the ECM does not monitor fuel pressure so no DTC set for this. Since it is 10 PSI below specs I can assume that this could be the cause. anyone else had to replace there fuel module due to these DTC's? 0 Quote Link to comment Share on other sites More sharing options...
FusionDiffusion Posted October 14, 2011 Share Posted October 14, 2011 ok so here is the latest. I swapped the MAF with a known good sensor. Code's still came back. Checked for vacuum leaks with propane and found none. I checked the fuel pressure with a mechanical gauge. Reading 38 lbs at idle at WOT (no load). Unable to test fuel pressure under acceleration today. Ford states fuel pressure range from 48-79 psi. unfortunately the ECM does not monitor fuel pressure so no DTC set for this. Since it is 10 PSI below specs I can assume that this could be the cause. anyone else had to replace there fuel module due to these DTC's? What was the pressure at KOEO (key on engine off)? Did you hear the pump run briefly when you turned the key to ON? Cycle the key OFF and back to ON (engine still off) and check the pressure again. Did the pump run again briefly and did the pressure increase? Idle pressure is 38 psi which is a little low but not terrible. You don't have to check the pressure at WOT, revving to about 3000 rpm in park should give you a good indication. Finally, what happens to the fuel pressure when you turn off the engine? Does it decrease? How fast? If you're having a fuel pressure problem, I would think you would have a noticeable loss of power at WOT? Is this the case? Unfortunately with this car there is no regulator and all the pressure switches and filters are all part of the fuel tank module. Has the car been sitting with old gas for any period? 0 Quote Link to comment Share on other sites More sharing options...
57fan Posted February 26, 2012 Author Share Posted February 26, 2012 well i thought I would finally respond to this post. I Checked the fuel pressure and it was 10 lbs below specs and no vacuum leaks so I went with a new fuel Pump Module..This car does not have a fuel regulator. It is a returnless system with no return lines to the tank. The pressure is maintained by the fuel pump Module. if the Pump is weak then so is the FP.. I found a Ford / Motorcraft fuel pump on Amazon.com for $139.00. could not believe they were almost $175.00 less than the local dealer. It was a quick repair and I have had no problems or CEL since. The day after I ordered my pump Amazon had raised the fuel pump to $189.00. Supply and demand for you. So if you are in need of parsts, dont forget to check Amazon. They have some good deals.. 0 Quote Link to comment Share on other sites More sharing options...
FusionDiffusion Posted February 26, 2012 Share Posted February 26, 2012 Glad you were able to find and fix your problem for reasonable cost (and thanks for letting us know what it was). I knew you pump was was a little weak but I guess 38 psi is pretty low when the middle of the range is 64 psi. On the older systems you used to be fine if you had more than 35 psi. I use Amazon occasionally for parts, but I also like RockAuto. 0 Quote Link to comment Share on other sites More sharing options...
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