+ Reply to Thread
Results 1 to 7 of 7

Thread: LM7 vs L59?

Hybrid View

  1. #1
    Join Date
    Sep 2009
    Posts
    12

    LM7 vs L59?

    i was under the assumption that all 5.3's were e85 ready. is this not true? i've been running it in MY 04 5.3 and its been doing fine. little less mpg and rough starts in very cold weather but i thought that was normal.

    whats the deal?

    1965 Mustang
    Bored, Cammed, and slammed!
    2004 GMC sierra
    RCSB 5.3 2wd
    LPP long tubes, offroad y, magna flow cb

  2. #2
    Join Date
    Aug 2007
    Location
    Honeywood, Ontario
    Posts
    6,994
    Different fuel rails, bigger injectors on the e85 motor.
    2006 Silverado
    Little Black Bitch

  3. #3
    Join Date
    Sep 2009
    Posts
    12
    im going to have to look at my vin, but if my engine was NOT e85, then would it still run the way it does?

    1965 Mustang
    Bored, Cammed, and slammed!
    2004 GMC sierra
    RCSB 5.3 2wd
    LPP long tubes, offroad y, magna flow cb

  4. #4
    Join Date
    Sep 2009
    Posts
    12
    i checked my build sheet and vin, i have the lm7 with a T in the 8th digit.

    1965 Mustang
    Bored, Cammed, and slammed!
    2004 GMC sierra
    RCSB 5.3 2wd
    LPP long tubes, offroad y, magna flow cb

  5. #5
    Join Date
    Aug 2007
    Location
    Honeywood, Ontario
    Posts
    6,994
    If your truck isn't meant/tuned for e85, running it isn't the greatest idea. At all. The stoich point for e85 is 9.7:1 whereas gasoline it is 14.7:1. This means your PCM is trying to command a 14.7 air/fuel mix. If it's commanding that on e85 it will be running dangerously lean.
    2006 Silverado
    Little Black Bitch

  6. #6
    Join Date
    Sep 2009
    Posts
    12
    needless to say, im not gonna run it anymore. Since this has happened, i think i may need to check my plugs then. could have damaged them with the lean conditions. currently at 51k on stock plugs. i really need a tune since i have no o2 sensors

    lean is mean though, right? lol

    1965 Mustang
    Bored, Cammed, and slammed!
    2004 GMC sierra
    RCSB 5.3 2wd
    LPP long tubes, offroad y, magna flow cb

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts