will basic changes cure an OVERLY rich condition??

Discussion in 'Fox 5.0 Mustang Tech' started by Foxfan88, Oct 22, 2007.


  1. Foxfan88

    Foxfan88 My Grandpa has great wood.

    Joined:
    Sep 13, 2004
    Messages:
    2,496
    Likes Received:
    0
    Trophy Points:
    0
    ok i am sorry to keep posting questions when i dont even have a tweecer yet, i am really planning to get one SOON. but have been reading on them so i am not totally lost.

    on my car i put a bigger SC lower pulley on and increased the output of the blower i have and while i was at it i replaced my stock 19lb injectors with 42s, i also ditched the FMU and put in a pro-m 75 mm MAF(shiny one) with the 42lb "blower" calibration.

    the car runs way too rich (as expected.)

    it was blowing black smoke out the tailpipes when i put a load on it and when i pressed the clutch in it would die when the rpms fell down. the 42s were working on their own ( no FMU) and provided enough fuel even under 8 psi to blow black smoke out the pipes, just to give you an idea of how rich it runs ( this could be partly due to the "blower" mass air sensor)

    i tinkered around manually with my idle and FP. adjusted the FP to about 35 psi or so. seemed to like it ok. i also jacked up the idle to about 1000 rpm.

    the car NOW will start pretty good, i dont have to feather the gas to keep it running on a cold start ( probably the overabundance of fuel causing this) and the car wont die when i press the clutch in approacing a stop. if i happen to kill it on accident it alot of times will flood out like a carbed car and its hard to start it again.

    the car is also getting horrid gas mileage.

    the car has also lost some power. it runs fast still but doesnt quite have the "edge" to it like it did.

    i can tell there is some hidden power in a tune.

    to my question finally.

    will changing basic parameters and scalars telling the EEC what i have done so far cure some of my fuel problems.

    i dont have a tweecer yet but it seems i can go in, tell the EEC i have 42lbers, set a good MAF transfer and set the injector high/low/breakpoint and all the other small/basic changes and this would get the AFR alot better where it should be (without getting in depths and messing with injector timing and pulse width) am i correct in my thinking???

    also with this 42lber "blower calibrated" sensor what am i going to do there? can i just set my own transfer or use a regular pro-m 42 lber table??? or should i send the sensor in for rewiring?? a little insight there would also be great.

    thanks for any help!
    #1
  2. vristang

    vristang Advanced Member

    Joined:
    Mar 31, 2005
    Messages:
    4,671
    Likes Received:
    7
    Trophy Points:
    69
    ProM should have sent the MAF Transfer with the meter, but sometimes you need to request them, so I'm told...

    Yes, you will likely see a majore difference in how the car runs after only making a few changes...
    Will it 'fix' your problems?
    Tough to say... We/you don't know exactly what the problem is...

    I have no experience with boost, so I may not be much help,
    but good luck,
    jason
    #2
  3. Foxfan88

    Foxfan88 My Grandpa has great wood.

    Joined:
    Sep 13, 2004
    Messages:
    2,496
    Likes Received:
    0
    Trophy Points:
    0
    the car is running too rich under all driving conditions. i can still drive it good and it will drive pretty decent. just will load up at low rpm sometimes and you can feel it "duh duh duh" when you start to give it some rpm under a load. until it clears it's throat and it will run better but still too rich. it feels lazy.

    i didnt buy the meter new i got it used so i will have to see about the transfer.

    i think in the meantime since i am untuned i will put the stock 19s back on with the FMU, it ran fine before, maybe a tad rich. i was afraid the 19s wouldnt be enough. but with the FMU i think it can take it for a bit. i want to at least get it to the track one last time before the season closes. to get a good baseline with the 8-9 psi

    then over the winter i will get the tweecer and toy with it and put the 42s back on it etc etc.
    #3
  4. ninety15.0

    ninety15.0 New Member

    Joined:
    Mar 11, 2004
    Messages:
    1,339
    Likes Received:
    0
    Trophy Points:
    0
    I think you should toss the 19's back on with the FMU. Running overly rich like that isnt good for the car either.

    You could make some very basic changes to the tune with a tweecer and see immediate differences in the way the car drives/behaves. This would include uploading the proper MAF transfer and changes all the necessary injector scalars. Also look into changing the fuel startup tables to cure the cold/hot start problems...most of which are associated with the injectors/MAF. Also battery voltage vs injector offset will help cure any problems stemming from the injector swap. Obviously setting the idle and startup scalars will help get the idle down to a more normal speed...although 1000 isnt horrible.

    Obviously your biggest power gains will come from tweecing the fuel delivery and load scaling. You will be well over 100% V.E. in boost...and making those changes to your load tables in the tune will really help you out. Obviously the end objective is to get that AFR around 12:1 to be safe and make some good power.

    With headgasket problems being all too common, i wouldn't be beating on the car too bad without a good tune. Good luck man
    #4
  5. Foxfan88

    Foxfan88 My Grandpa has great wood.

    Joined:
    Sep 13, 2004
    Messages:
    2,496
    Likes Received:
    0
    Trophy Points:
    0
    yeah i will toss the 19s and FMU back on for a bit and then once i get a tweecer i will tune it and put the 42s back on
    #5

Share This Page