GM TBI swap - I'm stumped

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  • elskeptico
    350 Buick
    • Sep 03, 2003
    • 821

    GM TBI swap - I'm stumped

    Looking for a little help.

    - AMC 360 (healthy pre-swap)
    - GM TBI junk yard parts and some new/rebuilt
    - 1227747 ECU and TB from a 1991 Chevrolet Sport Van G20
    - Used the 8-pin ignition control module and existing ESC with knock sensor
    - Distributor is welded and disconnected from vacuum
    - Fuel pump is brand new MSD mounted outside tank
    - Coil is new Delco HEI
    - Separate relays for fuel pump and other stuff

    I spent much of the weekend reading through posts and double checking my wiring and assumptions, but I still can't get it started normally. I don't have a way of datalogging yet, sorry.

    I have spark and fuel. No error codes.

    MAIN ISSUE: the only way I can get it started is if I set the distributor WAY advanced (like about 50 degrees), and give it throttle while cranking. I got it started (real rough) and kept it running to warm it up enough that I could check the timing at idle, which showed about 10 deg. BTDC. I drove it around the block, actually drove okay (not great), got it back in the driveway and turned the key off but...it kept running I was out of time, so I just pulled the fuse on the TBI stuff and it shut off.

    I'm assuming the fact that I couldn't shut it off means my ignition switch is bad. Anything else that could cause that? I suppose a stuck relay could do it.

    My hunch is a bad ignition module, but it's getting spark, so...

    Things I've already checked/calibrated:
    - All typical voltage checks (coil, injectors, ALDL)
    - TPS sensor adjusted to about .58V at idle
    - Coil (resistance checks found online, checks out fine)
    - System is well-grounded to engine block

    [I have not "reset" the IAC because that requires a running engine and I just barely got it running]

    There
    1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

    If you go lookin' for rust, you'll find it.
  • babywag
    out of order
    • Jun 08, 2005
    • 10286

    #2
    You may need a diode on the alternator wire to resolve the run-on with key off issue...had to do that on my 90GW.

    Try reversing the distributor pickup wires. They will cause big issues if reversed.
    Specifically, timing that is WAY outta whack.
    Tony
    88 GW, 67 J3000, 07 Magnum SRT8

    Comment

    • elskeptico
      350 Buick
      • Sep 03, 2003
      • 821

      #3
      Originally posted by babywag
      You may need a diode on the alternator wire to resolve the run-on with key off issue...had to do that on my 90GW.

      Try reversing the distributor pickup wires. They will cause big issues if reversed.
      Specifically, timing that is WAY outta whack.
      Thanks, I'll look into the diode.

      I've already swapped the pickup wires, actually, didn't help. Previously had purple going to P and orange to N, and switched them after seeing one of your prior posts about doing it the other way.
      1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

      If you go lookin' for rust, you'll find it.

      Comment

      • babywag
        out of order
        • Jun 08, 2005
        • 10286

        #4
        Distributor a tooth off? Or plug wires 1 position off?
        Tony
        88 GW, 67 J3000, 07 Magnum SRT8

        Comment

        • babywag
          out of order
          • Jun 08, 2005
          • 10286

          #5
          Also if this is a "new" made in China module YES it could be bad...
          many many instances of new aftermarket junk right out of the box.
          Tony
          88 GW, 67 J3000, 07 Magnum SRT8

          Comment

          • elskeptico
            350 Buick
            • Sep 03, 2003
            • 821

            #6
            Originally posted by babywag
            Distributor a tooth off? Or plug wires 1 position off?
            Plug wires, no. Tooth off is possible. One thing I couldn't find was what's the "optimal" place to set the distributor in relation to TDC for this swap? Like I said, I had to rotate it very advanced to get it to start/run at all.


            Originally posted by babywag
            Also if this is a "new" made in China module YES it could be bad...
            many many instances of new aftermarket junk right out of the box.
            The module I'm using was from the junk yard.
            1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

            If you go lookin' for rust, you'll find it.

            Comment

            • babywag
              out of order
              • Jun 08, 2005
              • 10286

              #7
              I run them @ 0 degrees and let the computer do timing.

              Some folks for whatever reason cannot do 0 degrees.
              If not 0 degrees the .bin needs to match the initial timing and the timing table needs to be correct to account for the difference.

              What is the .bin BCC#?
              Tony
              88 GW, 67 J3000, 07 Magnum SRT8

              Comment

              • elskeptico
                350 Buick
                • Sep 03, 2003
                • 821

                #8
                Originally posted by babywag
                What is the .bin BCC#?
                I had set it at or close to 0 initially, but couldn't get it to do anything until advancing it significantly.

                BCC is ARJV (or maybe ARJU). The Bin finder on gearhead-efi.com doesn't give any results for this BCC.
                1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

                If you go lookin' for rust, you'll find it.

                Comment

                • babywag
                  out of order
                  • Jun 08, 2005
                  • 10286

                  #9
                  ARJU sounds familiar CA-only .bin iirc

                  Have you checked for codes?

                  Do you have ability to read/burn or swap a diff chip?
                  Tony
                  88 GW, 67 J3000, 07 Magnum SRT8

                  Comment

                  • elskeptico
                    350 Buick
                    • Sep 03, 2003
                    • 821

                    #10
                    Originally posted by babywag
                    ARJU sounds familiar CA-only .bin iirc

                    Have you checked for codes?

                    Do you have ability to read/burn or swap a diff chip?
                    I don't have any codes, even after getting it started rough and driving around for a bit.

                    I don't have any chip burning capabilities yet, and no other chips to try. I might try to get to picknpull tomorrow and see if I can find another ignition module to try. Thanks for the help.
                    1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

                    If you go lookin' for rust, you'll find it.

                    Comment

                    • elskeptico
                      350 Buick
                      • Sep 03, 2003
                      • 821

                      #11
                      For clarity, I followed this wiring diagram almost exactly:



                      And here's how I did the coil wiring:



                      Even though the coil gets 12V+ from the black connector, I assumed it also needed a source through the bigger wire in the gray connector.
                      1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

                      If you go lookin' for rust, you'll find it.

                      Comment

                      • elskeptico
                        350 Buick
                        • Sep 03, 2003
                        • 821

                        #12


                        Okay, I'm an idiot. The engine run-on issue was due to the way I wired the coil (wrong).

                        Does the coil only require the pink and white wires that come from the ignition module (pink gets 12+ from relay)?
                        1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

                        If you go lookin' for rust, you'll find it.

                        Comment

                        • babywag
                          out of order
                          • Jun 08, 2005
                          • 10286

                          #13
                          Small wires from coil pink/white go only to module.
                          Should NOT get power from elsewhere.
                          Only large gauge coil wire should get power in crank/run positions.

                          Here is a GM wiring diagram I simplified many years ago.
                          Promised this to someone else, figured might be useful to others as well? New link, google changed things again... https://drive.google.com/file/d/0B7yskeUx6UviVUp0SWdDX1owbkU/view?usp=sharing&resourcekey=0-5K3XwxBm4bAaAqq4Lz8LBA
                          Tony
                          88 GW, 67 J3000, 07 Magnum SRT8

                          Comment

                          • elskeptico
                            350 Buick
                            • Sep 03, 2003
                            • 821

                            #14
                            Originally posted by babywag
                            Small wires from coil pink/white go only to module.
                            Should NOT get power from elsewhere.
                            Only large gauge coil wire should get power in crank/run positions.

                            Here is a GM wiring diagram I simplified many years ago.
                            http://www.ifsja.org/forums/vb/showthread.php?t=169223
                            Wow, thanks. I followed that diagram I found elsewhere (maybe binderplanet), guess it's wrong or I misunderstood it.

                            I have a relay for injectors, ECU, O2 sensor and ignition. Separate relay for fuel pump.

                            Should I have a third relay for ignition alone?
                            1979 Cherokee Chief S, 360, TFI, Part-time conversion, rust

                            If you go lookin' for rust, you'll find it.

                            Comment

                            • babywag
                              out of order
                              • Jun 08, 2005
                              • 10286

                              #15
                              Your choice...both mine only have/use 2 relays
                              Tony
                              88 GW, 67 J3000, 07 Magnum SRT8

                              Comment

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