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Thread: New engine reving problem

  1. #1
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    Default New engine reving problem

    Just recently, I had my 02 engine swapped with an 06 engine. The torque was great but reving at higher gear is a problem. My truck wouldnt go beyond 4000 rpm at ease. It takes a while time to shift from 3000 rpm to 4000+ rpm especially when I stomp on the gas all the way down. Is there anything on the tune that could be changed to help on my shifting problem??
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    Last edited by goldbergv95; September 4th, 2010 at 05:36 AM.
    2002 4.2L I6 Trailblazer LTZ

  2. #2
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    this started to happen after we installed a gibson exhaust. When I had the dual borla exhaust the shifts were fine.
    2002 4.2L I6 Trailblazer LTZ

  3. #3
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    Hmmm, anything else change besides the exhaust?

    If you just changed the exhaust then it could be a physical transmission issue. I would change the shift settings of the shifts to make sure the upshift and downshifts dont overlap. Also, I noticed your mph shift points are waay off, I barely got to 42-43mph at 6100rpms and 3.73 gears. No reason yours should be set to 46mph with your 4.10s. Change them down to like 40mph and smooth the shift points as well, I keep my mph set to 40 then use the RPM point to command the shifts at WOT.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

  4. #4
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    We installed the oem fan clutch back and swapped in a 06 engine.

    That is exactly what my tuner told me. He thinks that by fixing the trans caliubration it should solve the slow reving above 4000 rpm. I have the tune but didnt get a chance to test due to school just started.

    Ill test it this weekend and let you know. or maybe show you the tune we i convert it to efilive.

    Quote Originally Posted by ScarabEpic22 View Post
    Hmmm, anything else change besides the exhaust?

    If you just changed the exhaust then it could be a physical transmission issue. I would change the shift settings of the shifts to make sure the upshift and downshifts dont overlap. Also, I noticed your mph shift points are waay off, I barely got to 42-43mph at 6100rpms and 3.73 gears. No reason yours should be set to 46mph with your 4.10s. Change them down to like 40mph and smooth the shift points as well, I keep my mph set to 40 then use the RPM point to command the shifts at WOT.
    2002 4.2L I6 Trailblazer LTZ

  5. #5
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    Well coming from efans back to a fan clutch is going to make it rev slower, no doubt about it. That extra 10lbs sitting on the front of the engine hurts its ability to rev.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

  6. #6
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    Quote Originally Posted by ScarabEpic22 View Post
    Well coming from efans back to a fan clutch is going to make it rev slower, no doubt about it. That extra 10lbs sitting on the front of the engine hurts its ability to rev.
    Yeah one member from trailvoy found that out.

    BTW, i just got the tune and the truck drives great! I made log just to make sure everything is perfect.

    dyno.efi
    2002 4.2L I6 Trailblazer LTZ

  7. #7
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    I want efans so badly on the 02, but its now my mom's DD and soon to be the spare truck once again (maybe even delegated to duty in California, 3000mi from me! :( ). The only reason I havent done them on the SS is towing, I need the full towing capacity. Hmmm maybe Ill get efans and get a manual fan switch for when/if the temps start rising above where I want them.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

  8. #8
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    I think you can still tow with the efans. GC STR8 can tow with there efans.
    2002 4.2L I6 Trailblazer LTZ

  9. #9
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    Quote Originally Posted by goldbergv95 View Post
    I think you can still tow with the efans. GC STR8 can tow with there efans.
    Yea but we have tiny radiators which is where the problem lies. I probably would be ok with my 4000lbs boats and efans, but I dont want to chance it yet. When I can afford a better radiator then Ill do it all at once.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

  10. #10
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    Quote Originally Posted by ScarabEpic22 View Post
    Yea but we have tiny radiators which is where the problem lies. I probably would be ok with my 4000lbs boats and efans, but I dont want to chance it yet. When I can afford a better radiator then Ill do it all at once.
    Is that the reason why I lose so much coolant with the efans? I was begining to wonder if the efans were problem. But If i have the money I would ask a radiator company to customade one for us I6 thats if anybody knows a company that can do it...
    2002 4.2L I6 Trailblazer LTZ

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