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Thread: trans problems related to maf help please

  1. #1

    trans problems related to maf help please

    Hey guys, Need some help asap. I soon will have a Nelson tune, not having one has caused me grief.
    as soon has Allen gets back to me ill get a tune.
    in the mean time, I have some performance related issues that i got fed up with and wanted to correct. I spoke with the man who did my mail order tune about them. He sugested that I disconect the MAF senser and see if the problems whent away. I did this and drove the truck. 1000% pecent improvement. I reported the results and was waiting for an explanation and some remedey. He asked me if "my trans was shifting ok?" yes it was. Under his advise I just left it un pluged. This truck shifted fine for a day. Then acted like it had a mind of its own, But only retarded.

    I still dont know what the problem was/is that should be addressed.

    Ok... so I pluged the senser back in, no change, ...disconnect battery no change, ...checked fuses all ok, ....disconnect poss cable only no change ....dissconnect neg only no change.

    The truck will only shift if I let off of the gas momentarily. goes thru the gears like that. But At 60 mph high way merge, throttle down trans down shifts and pegs the rev limmiter. From a stop normal throttle acts like full throttle and pegs the rev limmiter. ( goes like hell better that ever) but no shift. Up a hill... additional gas, down shifts bust the tires loose pegs the rev limiter, and Its like right know. not enough time to get your foot of the gas. That truck revs quick and will most likely blow it self up and get me a reckless op traffic ticket or display of acceleration suspension .

    What happened to my truck? What was wrong or out of tune with it in the first place?

  2. #2
    bump

  3. #3
    I just reread this full article is at the link below.


    The Electronic Pressure Control (EPC) solenoid dictates shift characteristics by changing line pressure. The EPC receives orders from the VCM, which is continuously comparing sensor inputs against its stored algorithms and tables.In theory, this marriage of computer and transmission should provide the perfect line pressure for any situation; FLT has found in practice this is not always the case. The sophistication of the system is its Achilles' heel. An improperly oiled air filter is capable of bringing this system to its knees by oiling down the MAF wires and providing the wrong signal to the VCM, which can result in complete transmission failure. While FLT's approach may seem a step backwards, it removes several potential failure points and replaces them with the proven and dead-simple operation and reliability of a vacuum modulator. This is not to say the EPC solenoid should never be used; it will depend on your application.

    Installing A Blown Chevrolet Transmission - GM High Tech Performance Magazine
    99RCSB Broke because I wasted thousands and thousands of dollars on my truck.

  4. #4
    OOOOH wonderfull
    But what happened,??
    is it blown up??
    or the computer not communicating with the trans,??
    did it throw it into some kind of limp home mode.??
    WTF i dont get it.
    Did I possibly have the wrong maf tabels from day one??
    Why would un-plugging the the maf let it run like a raped ape?
    ( like it should have) started better, idled better, lots more power
    I put up with it running kinda ok for over a year, I just reached a point where it was time to get it running like it should and now I got an a$$ ache

  5. #5
    BTW its an 2004 5.3l 4l60-e
    some mods. comp cams 212 218 563 lift shortie headers
    port n polished dbw t body
    valve springs udrive pullies trans go shift kit and tci 2400 stall

  6. #6
    Casey 23 or sprayed 99 might be able to give you a better idea. They are most likely working on transmissions right now.
    This might not be your problem or it could be something really simple.
    Don't listen to any thing I say I don't know anything about mechanican. I only know how to mash the gas all the way down.
    99RCSB Broke because I wasted thousands and thousands of dollars on my truck.

  7. #7
    simple solutions needed
    just removed and cleaned the maf senser, good dousing with contact cleaner looked good before just as clean now. no change.
    is there a relearn procedure that i can do, a forced reset ?
    can i test the maf with ohm meter?? how and whats goog readings?
    how about the signals to and from the maf senser?
    simple solutions are the best, any are welcome, I have my nephews this weekend and my truck is broke. I'm afraid to drive it, you know get stuck kids bugging me to go, Pontiac nationals this weekend, 5 year old want his baseball trouphy from the city homedays. oohh this is not good.

  8. #8
    Join Date
    Jan 2006
    Posts
    2,602
    Quote Originally Posted by kst3v3n View Post
    simple solutions needed
    just removed and cleaned the maf senser, good dousing with contact cleaner looked good before just as clean now. no change.
    is there a relearn procedure that i can do, a forced reset ?
    can i test the maf with ohm meter?? how and whats goog readings?
    how about the signals to and from the maf senser?
    simple solutions are the best, any are welcome, I have my nephews this weekend and my truck is broke. I'm afraid to drive it, you know get stuck kids bugging me to go, Pontiac nationals this weekend, 5 year old want his baseball trouphy from the city homedays. oohh this is not good.
    Use an electric type spray cleaner and clean the MAF with it. The little sensors need to be clean free to work. As hot as it is outside, it should evaporate quick. Also your TPS or throttle position sensor has a lot to do on how your trans shifts. I had one go bad and it would slam into gear periodically and shift real hard. RED may be able to give you some insight on the problem. Undo the positive cable for like 20 mins and do a re-learn. Clean the MAF first with Electrical spray they have it at NAPA or just about any auto parts store.

    Hope this helps,
    Jamest
    12 Sec. Club! SOLD
    La Viuda negra/ a.k.a. Black Betty

    LQ4 6.0L, WCCH HEADS, LEVEL 5 FLT 4L80E TRANS. WITH TRANS BREAK, YANK 3200 STALL, TRICK TURBO, TURBONETICS T-76 TURBO, CUSTOM INTERCOOLED, 68lb INJECTORS, CUSTOM S/D TUNE FROM NELSON PERFORMANCE, COMP CAM 212/214 .557/.559 116+2, SNOW METH. KIT, . ALL INSTALLED AND DYNOED AT NELSON PERFORMANCE: 5**?HP @ 5073rpms and 5**TQ @ 4389rpms AT THE WHEELS WITH 10 PSI OF BOOST. ALL 3/4 TON TRUCK 5435LBS, NOTHING TAKEN OFF, STREET TIRES, AND USUALLY 2 BABY SEATS. WANNA RIDE?
    SOLD***

  9. #9
    MAF has a direct effect on shifting. your shifting problem is light throttle
    or just WOT throttle?
    check to verify the wiring to the MAF is not damaged.. did you get a MIL
    when it was unplugged? or have you always had a MIL on?
    DTC 101-102-103 are MAF codes plus you should have had some IAT DTC.
    the MAF also contains the IAT (intake air temperature sensor) unplugged
    the computer thinks its -40° intake air... fuels and timing accordingly
    seeing as your disconnected the cables (incorrectly) you now probably
    need a transmission relearn as well as a full system relearn.
    try this procedure...
    disconnect the negative cable (only) lead from battery
    disconnect any and all cell phones from the cig lighter jacks
    press the horn and brake pedal for one-minute or longer.
    reconnect the negative battery lead to battery.
    youll need appox 200mi to relearn all the adaptive learning sequences

    airdeano

  10. #10
    casey23 Guest
    You guys are on the right track ... something is wrong... anytime you talk mail order tune with shift kits and stalls ... it can get EVIL ... I have a 99 vette that goes wide open EPC anything past 50% throttle... it will not release or reset till you turn the key off.... Its in the tune !!

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