what would keep my car from switching out of closed loop?

Discussion in 'Fox 5.0 Mustang' started by cenok is family, Oct 1, 2009.

  1. cenok is family New Member

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    i was messing around with my car today to try and see if i can figure out my rich condition. i swapped out my distributor for another one i had laying around and it seems to be a tad more responsive (may just be placebo effect though) but overall it's still not all there. just for the heck of it, i unplugged my mass air sensor to see if that would change anything and literally absolutely nothing changed in my car's driving condition which leads me to believe it isn't switching out of closed loop after initial start up. am i correct on this? and if so, what would cause it to stay in closed loop mode? i have noticed that since i put the heads and cam on last summer, it doesn't seem to warm up all the way, at least according to my factory gauge. aside from that, what else could cause it? i want to check every possible variable. thanks in advance.
  2. HISSIN50 "How long do you think it'll take me to get any he

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    A couple of clarifiers. When you start the car, it's in open loop. That is, without utilized real-time feedback from the O2's. The O2's light off as a function of time, not engine temp. This takes 30-120 seconds with our HEGOs.
    Once the O2's begin to be utilized (within two mins), you're in closed loop.

    Disconnecting a MAF and having nothing change suggests perhaps the MAF itself is bad. The MAF is a primary sensor - it is always used and the EEC is hurting for any sort of way to figure out real time air flow if the sensor is bad.

    If you haven't, start with codes. Note that you might have generated your own batch of artificial codes with the MAF disconnect.

    Good luck bud.
  3. cenok is family New Member

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    my bad, i always get the two confused. mod's if you'd change the title i'd appreciate it.

    ok, so i was reading over the info on fordfuelinjection.com and i must have gotten something backwards. the maf is used from the get go? i thought it was ignored while in open loop because the EEC looks at the ECT and ACT to determine the amount of fuel needed, according to fordfuelinjection. i guess i just misunderstood it. ok since that is straightened out, i have an idea of what to look at. my maf is a reman sn95 unit i got from autozone when i worked there. i got it because i looked at it when it was in the box and it still had ford electronics on it. so i really don't think it's the culprit in this case...i think my wiring may be an issue. when i did my mass air conversion, i used butt connectors and splice connectors (i know, i know) so i'm thinking maybe something either disconnected or didn't fully splice into the wires they were piggy backing off of. it would make sense because she's ran rich since i built the motor and did the conversion, and i've tried FOUR different mass air sensors/fuel injector combos on her and she was pig rich every time. i really doubt they were all bad. thanks for the info hissin!
  4. HISSIN50 "How long do you think it'll take me to get any he

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    Yep, the MAF is used at all times. It's one of the most important sensors on the car.

    If you have a link to what you read and want to, post it so we can see what they were saying.

    FFI and Jrichker have info on testing the MAF if you want to do that.

    What codes do you get?

    Have you had the LT's for awhile? They can allow O2's to cool down after an extended idle.
  5. cenok is family New Member

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    Hissin, you are a GODSEND!!!! what you just told me helped me to finally realize and fix the problem! it wasn't the meter....it was the wiring! like i said, when i did the conversion, i used the stupid splice connectors to splice the power and ground wires for the maf harness into the main harness. well i just pulled my ecu and looked at my splices...the connectors didn't even break through the wires' shielding! so the mass air sensor didn't have any power at all! the maf sensor was pretty much just for looks! i pulled it all and redid it, soldering it this time. man, she runs SOOOOOOO much stronger now! and no more gas smell!!! there's a little bit of a surge at idle but i imagine the ecu has to adapt to and recognize that there is a maf sensor there now. i've been chasing this for over a year now and i finally have the issue resolved! now i can get a real tune on it! thanks soooo much man!

    on a side note, my car put down what it did in my sig with a disconnected mass air sensor...i wonder what it'll put down now? :D time to put the 24# injectors and pro-m sensor back on!
  6. HISSIN50 "How long do you think it'll take me to get any he

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    Glad to hear you methodically figured it out and fixed it. :nice:

    With that A/F trim from your pull, I'd say you were running a little fat. :rlaugh:
  7. cenok is family New Member

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    haha yeah i'd say so. thanks again man, i'll post up what she puts down when i take her back for a tune here in a couple weeks.
  8. poulrais New Member

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    On another subject, I can see from your pics you have the SSC-4 wheels on your car... I'm planning on buying the 17X10 rears and 17X9 fronts. Do you like thse wheels? Where did you get them? I saw them on Cruizingconcepts Website and the pricing is pretty good...
  9. cenok is family New Member

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    yeah i really like the wheels. i get compliments on them ALLLLL the time. those are the exact sizes i have and i got them from cruizinconcepts too. i say go for it!

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