{youtube}nYN-RoFVwAA|615|345|0{/youtube}

1999 Mercury Mountaineer 5.0 with a P0171 and P0174 DTC in memory. This is a great video on using fuel trim and freeze frame data to determine the cause of the lean condition.

Engine Performance Diagnostics chapter 4 pages 12-19

symptoms 50

  • low power
  • lean exhaust trouble codes P0171 and P0174
  • pinging
  • hesitation
  • surging

fix 50

  • replace fuel pump and fuel filter

test shown enh 50

  • how to determine MAF sensor condition using BARO HZ data
  • how to use freeze frame data to determine type of lean condition
  • how to use STFT and LTFT at different loads to determine type of lean condition
  • how to test fuel pressure with a gauge
  • how to determine fuel delivery design
  • how to measure fuel pump current with a scope
  • how to locate the fuel pump inertia switch
  • how to calculate fuel pump RPM

Tools used

  • scan tool
  • fuel pressure gauge
  • Picoscope
  • inductive low amp probe

end faq

{accordionfaq faqid=accordion15 faqclass="dotluvfaq help2 aligncenter headerbackground headerborder contentbackground contentborder round7" active=item0}

Playlist

(Chapters 14, 15,16) Fuel Delivery and Fuel Pressure Testing

Related videos:

Low Fuel Pressure from a bad fuel pump ground (Ford Ranger):

{youtube}rQ7tvIxQSt0|615|345|0{/youtube}

Symptoms and Causes of Low Fuel Pressure (Part 1):

{youtube}RyEPOeQB0Zg|615|345|0{/youtube}

Symptoms and Causes of Low Fuel Pressure Part II (new fuel pump) :

{youtube}EAvoz4kqw9g|615|345|0{/youtube}

How to test an electric fuel pump (1997 4.3L Chevy Blazer CPI):

{youtube}yjQY613sql4|615|345|0{/youtube}

end faq

{accordionfaq faqid=accordion3 faqclass="darkhivefaq defaulticon headerbackground headerborder contentbackground contentborder round5" active=item0}


For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available as an eBook or paper book.

Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium. There is a 14 day free trial.

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!