Results 1 to 6 of 6
  1. #1
    Join Date
    Aug 2013
    Posts
    2
    Country Flag: United States

    LT4 swap into a 1972 camaro

    long time member - not a big poster. cant believe ill be the first on the ltx forum, i appreciate everyones suggestions.

    so i bought a crate lt4 motor from GM and the ecu kit (the one w/ the pedal etc)



    everything is installed, all wires are connected, primed the motor, new battery, and grounds separated, have fuel pressure, and oil pressure,
    engine will crank but not turn over
    when i turn the key to one click the red LED light on the 'fuse box' blinks...and when i turn to start it shuts off.

    hooked up to a scanner
    no spark
    no injector pulse

    cant seem to figure out whats going on. anyone that has any suggestions im open to anything at this point. i realize this has a lot of technical specifications and questions, even if someone would have a number to call or contact info on more in depth trouble shooting it would be great. i reached out to GM performance and went thru their suggestions and didn't get any closer.

    thanks in advance.


  2. #2
    Join Date
    Apr 2001
    Location
    The Druid City
    Posts
    14,500
    Country Flag: United States
    Quote Originally Posted by mxb401 View Post
    long time member - not a big poster. cant believe ill be the first on the ltx forum, i appreciate everyones suggestions.

    so i bought a crate lt4 motor from GM and the ecu kit (the one w/ the pedal etc)

    everything is installed, all wires are connected, primed the motor, new battery, and grounds separated, have fuel pressure, and oil pressure,
    engine will crank but not turn over
    when i turn the key to one click the red LED light on the 'fuse box' blinks...and when i turn to start it shuts off.

    hooked up to a scanner
    no spark
    no injector pulse

    cant seem to figure out whats going on. anyone that has any suggestions im open to anything at this point. i realize this has a lot of technical specifications and questions, even if someone would have a number to call or contact info on more in depth trouble shooting it would be great. i reached out to GM performance and went thru their suggestions and didn't get any closer.

    thanks in advance.
    Where ever you hooked up the ECU "power on" wire (whichever it is in the GM harness) is not connected to the proper source. It needs to be connected to a switched source that is hot in both RUN and CRANK. So when you go to crank it over, the starter spins, but the ECU shuts off.

    Andrew
    1970 GTO Version 2.0
    1967 Cougar build
    GM High-Tech Performance feature
    My YouTube Channel Please Subscribe!
    Instagram @projectgattago

    "You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her

  3. #3
    Join Date
    Nov 2006
    Location
    Mountain Springs, Texas
    Posts
    3,240
    Country Flag: United States
    X2. You should have tapped into a pink wire.

    Don
    1969 Camaro - LSA 6L90E AME sub/IRS
    1957 Buick Caballero - huge project
    1959 El Camino - Ironworks frame
    1969 Mustang Sportsroof
    1956 Cameo - full C5 suspension/drivetrain

  4. #4
    Join Date
    Aug 2013
    Posts
    2
    Country Flag: United States
    thanks to both of you...fired right up. runs great!! cheers!

  5. #5
    Join Date
    Jul 2013
    Posts
    25
    Country Flag: United States
    I made this exact same mistake when I did my lS3. Doing an lt4 swap now on another car. Can't wait to fire it up

  6. #6
    Join Date
    Jun 2010
    Location
    Deployed
    Posts
    3,122
    Country Flag: United States
    Curious to see pics? What did you do for the accessory drive?
    1970 Camaro/DSE build


    Are you driver enough? Maybe....come on blue!
    https://www.pro-touring.com/threads/...71#post1147371