engine performance

Discussion in '94-95 5.0 - Specific' started by 98-5.0, May 17, 2007.

  1. 98-5.0

    98-5.0 Member

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    ok ive been runnin my 98 with the 5.0 for about 7 months now with no problems at all since the swap......but now im wantin to fine tune some things.....i hooded up my air fuel gauge today and im not very happy.....it goes lean on full throttle......and at idle it has a hince of white smoke....but if i was runnin that lean.......im sure it would have blown up by now cause i beat the crap out of that little motor........i set the tps and cleaned my iac.......made a little difference......but i am still runnin the v6 02's i know i should get the right ones.....do you really think that is the problem....cause it runs great and idles perfect almost........at about 900.......i have o/r h pipe and took out all the emissions.....and im still runnin stock t4mo computer.....let me know what you think.....cause id like to get it figured out soon ....even though ill be dropin a 357 twin turbo in it..........should i get some kind of tune...or what could i do ....i do have a buddy with a original 94 gt if you think i should swap 02's and see what happens first......get back and give me your 2 cents....
     
  2. 98-5.0

    98-5.0 Member

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    i just found out that the 02's are pretty much the same............well.......part store/part number.......im leanin more towards the no cats and emissions.....but there is no mil light..........i unpluged stuff like maf....iac...tps...and stuff...and it all made a difference.....the maf didnt make to big of one but it threw a mil lamp till i pluged it back in and keyed it .........but one thing ive noticed is the egr.....when i unplug it ...it dont do nothin at all........and im not 100000%sure the emissions selenoids in the fender are the right ones...but they pluged in......so now im kinda left hangin.....im kinda wantin to replace the head and intake gaskets just for the fact the motor sat for 7 years before i got it and with only 40k on it........i know my motors but this one is pretty much stumpin me pretty good.....i just dont get the pegin to the lean side at wot......it does sweap on normal drivin conditions and when i let off it goes to rich for a second or two.........
     
  3. Downshift

    Downshift Well-Known Member

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    Wow man, so your running V6 o2s and is that the 5.0 stock computer or something else. The 5.0s didnt have 4 o2s so I think that answers a question in there somewhere. Is it just an autometer Air/Fuel gauge? If so those are not that accurate so best thing to do would check out the Fuel pressure and take a peak at your plugs right after a hard run. Cant let it idle or anything gotta pull them RIGHT after to get a good reading from the plugs. My idle is at 900 and it feels WAY to high. I need to fix it because it was at 700 and that seemed perfect. I believe the idle is supposed to be at least below 750?

    If the o2 part numbers were the same then they are the same no sense in changing them out for the fact of them being v6 ones. If you think its because they are old or going out then couldnt hurt, they arnt hard to change at all.
     
  4. ryclef331

    ryclef331 Well-Known Member

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    like said before, what A/F Gauge are your running? Narrow or Wideband? I don't know 100% about the o2s but do you have an adjustable fuel pressure regulator?
     
  5. 98-5.0

    98-5.0 Member

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    no i dont have a adjustable fuel regulator but i know i need to invest in one....but im want to get one to work with my new 351 setup as well.......and off topic.............i want to pull my 89 fox back to a street car and retire it from drag.....will the 4cly body harness work....what harnesses for the v8 will i need....headlight, engine, computer and battery and tranny...?..........