cold starting/detonation/hesistation problem.

Discussion in 'Fox 5.0 Mustang Tech' started by staticc, Dec 21, 2003.

  1. before i explain the problem. ill explain what ive tried.
    took it to my friends shop. pulled following codes.
    67, 85, 91, 185.. it would not complete the running test.
    (you can read further on this at earlier thread i made )

    i replaced the o2 sensors, cap, rotor, sparkplugs (with autolite 25s)
    ..cylinder #6's plug was covered in white ash. that wouldnt scrape off.. i kept it incase you all want to see it...
    the rest were just normal wear.

    things i noticed. whoever had my car was dumb. i dont think the right ford plug wires were connected to the right cylinders. a boot had duct tape on it. some had burn marks. and he has them tied together with one of those plastic ties.. thats right, all tied close together so they dont sag and hit the headers i guess.

    NOW, to the problems..
    when i start it and its not warmed up. it will stall 3-4 times (more when colder outside) before it will idle roughly but not stall.. i have to blip up the rpms so it wont stall, and warm up. when its like this it hesitates pretty bad.

    after 5-10~ minutes the idling will smooth out. and become drivable, and the hesitation will get alot better.

    now, when im driving. it acts up at low rpms.. below ~2,500 sometimes. this seams to come and go....
    sometime i will start hearing popping in my longtube headers and it will not accelerate at all, or very very slowly. (SUCKS IN TRAFFIC WHEN THIS HAPPENS)
    but if i can get it to accel to 2300+ or so it smooths out and starts to pull hard.

    when it does this. i downshift to up the rpms. and it accels fine :shrug:

    if you think you can help with the cold starting problem, or the detonation(if thats the popping?) please do..
    its a real pain in the ass to wait in the car for 10+ minutes to get to work, then 10+ to leave work


    .. when i get home tomorrow (monday) ill check that cylinder #6's plug and see how its doing. and try and fix the sparkplug wires. and not have them bunched together. and get them on the right cylinders.
  2. It's really hard for me to diagnose the problem without me being there. Popping through the headers eh? Sounds like it could be a vac leak, worn timing chain, misadjusted timing, or worn cam bearings or lobes. Sounds mainly like an ignition problem due to the #6 plug fouling out.
  3. ill toss my two cents in. i was chatting with a buddy earlier (guy knows his stuff pretty well). he was talking about an improperly functioning egr, and listed many symptoms you do. i dont know what codes you got (too lazt to look them up), but just something to think about (i try to remember stuff that Michael Yount, et al, have said about them in the past, but its 3:30 and i need sleep.

    good luck. ill see if something makes sense after sleep (when i can remember my name. too many hours lookin at electrical schematics).

  4. the codes are looked up in the thread i linked to.
    and my egr is blocked off :shrug: