Results 1 to 15 of 46

Thread: Looking for Help!!! SBC TBI Cant get over 2300 RPM

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Electronic Ignition!
    Join Date
    Aug 2022
    Age
    36
    Posts
    12

    Looking for Help!!! SBC TBI Cant get over 2300 RPM

    Hoping a lot more knowledgeable than me can look this file over and see if anything stands out. I am very mechanically inclined but this is my first rebuild with almost zero help other than what i could find on youtube and forums. Please let me know any specific info that could be helpful thanks in advance.

    Background.
    1991 Chevy K5 Blazer SBC 5.7l
    engine was rebuilt and bored .030 over and converted to hydraulic roller
    has new heads from summit
    new distributor
    new temp sensor
    new map sensor
    new alternator
    new plugs
    new plug cables
    new fuel pump - tested ok with rented fuel pressure gauge from parts store - replaced all rubber lines to fuel pump
    new icm - have back up just incase both checked out good at the parts store
    etc...

    The issue i have is when get over a certain RPM is starts to misfire and "bog out" around 2275 rpm

    Wiring has been checked and re checked
    I did pull timing connector to verify timing and i believe that set the code 42 error code or it came on when I hit 2275 rpms not entirely sure. The test I did previous did the same thing as far as bogging out or miss firing but did not throw a code.
    I have fought this issue for a while finally found tuner pro to try to better understand whats going on only im not entirely sure how to read all the data. I can tell that my BLM is low not around the 128 it should be but not sure if thats related to my issue with the bogging down.
    Attached Images Attached Images
    Attached Files Attached Files

  2. #2
    Super Moderator dave w's Avatar
    Join Date
    Feb 2011
    Posts
    6,268
    The data log is showing two Errors Code 42 and Low Battery Voltage.

    The Code 42 happened about 2/3 of the way thru the data log. The Low Battery Voltage happened near the end of the data log.

    Attached is a Modified ARJU 91 C-G-K-R-V Truck 5.7TBI 700r4 california.bin with the BPW and SA patches applied. Possibly you have the ability to reprogram the chip with the attached .bin file?

    The BPW and SA patches are very helpful to see what the fuel and spark are doing at the moment Code 42 is set. The low battery voltage might be due the way the computer is wired to battery +, not sure. Low battery voltage is an unusual error to see in a data log.

  3. #3
    Electronic Ignition!
    Join Date
    Aug 2022
    Age
    36
    Posts
    12
    Yes, in the thread I mentioned that I unplugged the timing connector to verify base timing was at 0, Im pretty sure thats what thru the ignition control circuit code and the low battery was because I turned the key off before stopping the data log. I will try the bin file you attached and do a another data log and this time I will stop the log before turning the key off. Thanks for the reply.

  4. #4
    Electronic Ignition!
    Join Date
    Aug 2022
    Age
    36
    Posts
    12
    Looking at the Bin file you sent I cant see any difference from the one I was using. I believe the Bin file I was using had Spark advance and BPW can you please explain where I can can see the difference. thanks for the help!

  5. #5
    Super Moderator dave w's Avatar
    Join Date
    Feb 2011
    Posts
    6,268
    Screenshot using TunerPro's difference / compare tool.

    BPW Hack.JPG

  6. #6
    Super Moderator dave w's Avatar
    Join Date
    Feb 2011
    Posts
    6,268
    Perhaps the screenshot below is helpful too?

    BPW Hack_02.JPG

  7. #7
    Electronic Ignition!
    Join Date
    Aug 2022
    Age
    36
    Posts
    12
    Quote Originally Posted by dave w View Post
    Perhaps the screenshot below is helpful too?

    BPW Hack_02.JPG
    lol well now i really feel dumb didnt know there was a "difference tool" thanks for sharing. Ill do another test run/data log and repost. thanks for help!!

Bookmarks

Posting Permissions

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