How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask HDGENE Your Own Question
HDGENE
HDGENE, Ford Senior Master/Diesel/Trans
Category: Ford
Satisfied Customers: 4847
Experience:  25 years Auto experience, Ford ,GM, Chrysler, Asian & European
285738
Type Your Ford Question Here...
HDGENE is online now
A new question is answered every 9 seconds

F150: I have a 2001 ford f 150 with a 4.2 liter engine, code

Customer Question

I have a 2001 ford f 150 with a 4.2 liter engine, code po172 keeps coming back, fuel pressure has been tested and is good both koeo and koer, fuel pressure regulator is doing its job, fuel trims are lftrim1-17 and sf trim 1 -6 lftrim 2 is +5 and sf trim 2 is +2 koer
I did a smoke test for any vacuum leaks none found, sprayed carb clean around intake and hoses no leaks, fuel pressure pulse width bank 1 3.3 ms and bank 2 4.6 ms, maf was disconnected and engine ran no change to readings, reinstalled, air filter is correct, I am leaning towards possible fuel injectors on bank one . something is causing rich and I see no cause or failed component. egr is good no leaks, need a few ideas as to what may be the cause.
Submitted: 1 year ago.
Category: Ford
Customer: replied 1 year ago.
o2 sensors have been replaced , and sensor on bank 1 shows rich condition, fuel pressure stays steady and stable with koeo and koer , all with in spec. MAF at 28.6
Expert:  HDGENE replied 1 year ago.
Hello, if you give it a vacuum leak does the readings change? What is the baro pid read hertz and maf at idle?What is the load pid at idle with ac off?
Customer: replied 1 year ago.
baro is 28.6 I have not induced a vacuum leak yet but I will.
Expert:  HDGENE replied 1 year ago.
Ok i want to know what the baro hertz readin is should be around 155 based on altitude
Customer: replied 1 year ago.
Bari is 153
Customer: replied 1 year ago.
With a vacuum leak sf trim 1 went to plus 33. Lf trim 1 went to minus 14 then to plus 6 then back and forth
Expert:  HDGENE replied 1 year ago.
Ok so it recognizes a vacuum leak but normally the bank 1 side of the engine is running rich, the oxygen sensor is pinned at a higher voltage or does it fluctuate at a higher rpm? whats the load pid at idle around 17 %?
Customer: replied 1 year ago.
Load with vac leak 14 and Lf trim 1 is now 0
Customer: replied 1 year ago.
O2 on that side is 8 mc
Expert:  HDGENE replied 1 year ago.
Ok and its around 17 load without a vacuum leak or its running around 14. Injector pulse width the same on both banks? can you do a relative injector flow test or fuel pressure leakdown test?
Customer: replied 1 year ago.
With vacuum leak both sides Lf and sf are at 0
Customer: replied 1 year ago.
Right bank 1 is 3.3 ms and bank 2 is 4.5 ms
Customer: replied 1 year ago.
Vacuum hooked up now Lf 1 is minus 12 at idle and lf 2 is positive 6 sf 1 is minus 6 and sf 2 is positive 7
Customer: replied 1 year ago.
Runs better with vac leak but need to know possible cause
Expert:  HDGENE replied 1 year ago.
Block off the egr valve vacuum source and see if it improves, possible blockage in the egr passages of the lower intake, if no change suspect an issue with injector flow which would require injector flow test and fuel pressure leak down, all else checks good, eithe mass air flow issue which could be cleaned and retested or pcm concern
Customer: replied 1 year ago.
E g r. When opened changed idle and maf has been replaced how would pcm just affect one side of engine is it possible to have injectors causing issue
Expert:  HDGENE replied 1 year ago.
disconnect egr, each cylinder has a port in the intake, if clogged can affect drivability
Customer: replied 1 year ago.
ok I understand , but this is only at idle with a rough run, egr I think does not have vacuum apply at idle, so if egr is ok is this leading to an injector dripping fuel on that bank and causing just bank 1 to be rich. I am going to do a drop test on that bank, in the past we had to change an injector on bank 2 because it was stuck open , then months later the rich bank 1 comes into play. it runs fine at off idle and cruise , because im in the gas using what its dropping into bank 1 , but then at idle runs rough and has rich issue. does this sound like injector or is there a flash update to eliminate this issue. thank you I await your reply.
Customer: replied 1 year ago.
I'd like to ask again I have looked at e g r fuel pressure. M a f. Vacuum leaks misfire air filter and injectors I don't see anything obvious as to why at idle it's running so rich on bank one and bank two is fine any ideas
Expert:  HDGENE replied 1 year ago.
Yes it can be which is why I mentioned checking fuel pressure leakdown and injector flow if you can
Customer: replied 1 year ago.
I did a leak down each injector on bank 1 was 20 lbs leak down each I can't flow the injector would a Im rc valve not opening cause rich. The computer is as lean as it can go and. Injectors are soaking wet on bank one plug 1is pure white 2 is tan and 3 is brown looks like. Number 1 injector is not putting fuel in and pcm is telling add fuel which is too much. I'm trying injectors in bank 1 to see if helps I find no other issues wrong
Expert:  HDGENE replied 1 year ago.
Very good. Id be concerned bout the #2 n 3 plug being brown possibly from burning oil, the white number one sounds lean for sure

Related Ford Questions