Tuning Nightmare Please Help

Discussion in '94-95 5.0 - Specific' started by scsam44, Apr 3, 2016.

  1. scsam44

    scsam44 New Member

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    Well Ive just about had with getting a proper tune on this car. My 95 gt has a stock bottom end with full H/C/I. I originally had it tuned a while back by my buddy who is a certified SCT dealer, the only draw back is he doesn't have a dyno. The dilemma is on the first tune the car still had a stock throttle body and the tune he put on it was actually decent. It fixed most drive-ability probs and the car picked up a lot. Fast forward 6 months a I picked up a 70mm BBK. I drove the car on the original tune for a while and it was only lean at WOT. Had the car retuned 2 weeks ago and its gone down hill fast lol. Idle and WOT air to fuel is perfect. But the problem occurs randomly when cruising at partial throttle, it'll have great mixture and suddenly will shoot to stupid rich like 10/1. But as soon as in come to a full stop and take off it resumes proper air to fuel :undecided:. I spoke with him and he claims hes done all he can do. Also i should ad the car has horrible cold starts and restarts. Weighing my options as to whether I should take it to a chassis dyno or am i just beating a dead horse with this thing. Pro Dyno is about an hour from me but ive heard some on the fence things about their push rod tunes. Oh and also its running the lovely T4MO.
     
  2. Rob04Mach1

    Rob04Mach1 New Member

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    It's easy to get a canned tune for a basic GT with Basic Bolt on's, but once you get into Heads, Cam, Intake, TB, (and I assume Inj's, Maf, & FP), you really need to get it on the rollers and have a tuner with Modded Mustang experience. You said it has horrible cold starts (your words) that may be a clue.

    The ECM is in Open Loop on cold starts and does not adjust based on info from the 02 Sensors, instead it calculates the A/F and timing based on factory predetermined settings which get most of it's input from coolant temp and the MAF. Problem is once you modify to many things now the tuner has to mess with Open Loop tuning and a lot are not good at it. Once it warms up and goes into Closed Loop your MAF & O2 Sensors play a huge part on adjusting A/F so first place I would look is there. If the 02 Sensors & MAF are good then you have to find a good tuner to fix you up


    How old are your 02 sensors ? Do you run C10, C12, or C16 Fuel once in a while ? What MAF, Inj's, & FP are you using ?
     
  3. scsam44

    scsam44 New Member

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    Recently replaced o2 censors. The MAF is a Pro M, 24lb bosche injectors and a 190LPH FP. Im just coming to the conclusion the guy who tuned it probably wasn't the best choice for a motor with full top end kit on it. I'm gonna try and get in touch with Dan at pro dyno and see what he hays to say.
     
  4. white95

    white95 Apex Junky Admin

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    [MENTION=8201]Addermk2[/MENTION] may have a few suggestions
     
  5. ttocs

    ttocs Legend

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    Sounds like the problems came after the new TB? I sold a TB recently that I am not using on the new build and was kind of surprised to hear from the buyer he was having high idle issues like I did. Not sure what the problem was other then to say it was a pro-products tb really and that you can get the reducer plate or idunno. Try throwing the stock back on and see what happens. It might just be as simple as the bbk is too big or that it just isn't working with your combo.
     
  6. AzzLyp

    AzzLyp Member

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    Have you checked your coolant temp sensor? For shits and giggles, check that first. It's free to check the resistance on it. If it's bad, it will give you cold start problems.