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Thread: Flex Fuel swap, can't make it run. Please Help

  1. #1
    Tuner in Training
    Join Date
    Feb 2016
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    27

    Flex Fuel swap, can't make it run. Please Help

    I have been at this for days. I'm running a P59 on a turbo SBC and have been for months with the 2 bar enhancement. About 3 weeks ago I swapped to 3 bar and the car still ran fine. I have a gas station 20 miles me that has e85 at the pump so I upgraded to twin pumps, paid out the rear for some FIC 1200cc injectors and installed the fuel composition sensor. Enable flex fuel in the tune, re flashed thinking I was about to play and..... no content reading. I quickly figured out that I couldn't just enable flex fuel and go to work tuning. After some research I downloaded a 2002 Tahoe tune that has flexfuel enabled. I went back to my PCMs stock tune and did the segment swap for the engine and fuel system as well as the trans segment(4l80e) from the file I used way back whenever. I did the 3 bar enhancement, copy and pasted everything from my last tune and did a write entire thinking NOW I"M GOOD TO GO.....NOPE. I did now have fuel composition reading which seems close. (had about 3 gals of 100% gas and then added 5 gals of whatever the e85 mixture actually was from the pump.)
    anyway, the car wouldn't fire off and run for more than a 2 or 3 seconds. I ended up going back to the last NO Flex tune and the cars runs fine other than was about 15% lean. added 15% across the MAP and was good to go. Figured maybe I had a file so I searched for another flex fuel download and today went back over the whole process again with the same results.
    I don't know what do at this point other than go back to my last working tune and stay on 92 with low boost.

    The setup is a 383 SBC with DBC, 3 bar map, FIC 1200cc injectors with their data, 4l80e trans, twin 450lph pumps and a pair of 70mm turbos. the car runs fine on the LAST NO FLEX tune below.
    The 1479191873 tune was the flex fuel segment donor.
    Flex Fuel 3 was the 3rd attempt(more like 30th)
    flex test 3 log was me trying to fire up on the FF3 tune.

    For whatever reason the WB02 refuses to stay ready so that data is junk mostly but look at the commanded EQ and especially the barn injector pulse. don't make sense to me.

    I open to any and all suggestions. Thanks in advance.
    Attached Files Attached Files

  2. #2
    Tuner in Training
    Join Date
    Feb 2016
    Posts
    27
    Well, I guess I'll just find another flex fuel tune and start fresh....again.
    This time maybe I'll burn a couple credits and use a flex fuel tune instead of segment swapping into my tune. Gotta try something.

  3. #3
    It appears to go lean just before it goes dead. Are you sure that it's failing the MAF properly? Are you getting a P0103 code?
    If not...Instead of No Error Reported, change the P0101, 102 and 103 codes to MIL on First Error and try again.

  4. #4
    Tuner in Training
    Join Date
    Feb 2016
    Posts
    27
    Quote Originally Posted by kevin87turbot View Post
    It appears to go lean just before it goes dead. Are you sure that it's failing the MAF properly? Are you getting a P0103 code?
    If not...Instead of No Error Reported, change the P0101, 102 and 103 codes to MIL on First Error and try again.
    I guess with all the segment swapping and and such trying to get fuel content working I didn't realize I changed that. Its clearly "NO MIL LIGHT" in the tunes that run and "No error reported" in the ones that don't.

    Thanks for taking time to look at this and catching that.