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Finally able to datalog the CCC Carb ECM in my 87 Z28. It came with the same 1228079 ECM as the 87-88 MonteCarlo SS. The 8079 ECM is considered an upgrade for us E4ME carb guys, but accessing the datastream works a bit differently than the more common TBI/TPI. I figured I'd consolidate the info I found over various websites and forums.
When my 305 LG4 spun a bearing, I swapped in a Vortec 350 with an LT1 cam and shorty headers and kept the E4ME carb setup. Being able to log data allowed me to disable EGR, AIR, and get the spark timing map dialed in. I had an OTC Scanner 2000 but it would disconnect whenever the engine went into closed loop.
The 6-pin connector came unassembled. I removed the bottom pins by straightening them with pliers and pulling them out from the front. I had to grind the remaining pins with a Dremel and cutoff disk to fit the ALDL port spacing for pins A, B, and D. Most GM ECUs use pin E for the datastream, but the 8079 is one of the ECMs that uses D. A file would have also worked since the metal is pretty soft. I soldered a 10k ohm resistor directly between the A and B Pins. The Black ground wire is soldered to pin A, while the White signal wire was soldered to pin D. I used two pieces of adhesive lined heatshrink to protect the wires from the little clamp that keeps them from getting pulled out.
I installed the VCP Driver on my Windows laptop then plugged in the USB cable. (DON'T plug it into the car yet) I found the adapter in Windows Device Manager and set the rate to 4800. Fired up WinALDL, found the correct config settings and fired up the car. Plugged the cable into the ALDL port and started seeing data! Works in TunerProRT too.
FYI, in ALDL mode, the stock PROM applies a fixed timing advance which makes tuning difficult. Info here on PROM edits to disable that along with EGR delete. https://www.montecarloss.com/communi...30#Post1027530
I followed this thread to burn new PROMs: https://www.montecarloss.com/communi...&Number=888945
Windows Device Manager. Bits per second: 4800 WinALDL Configuration. Select same COM port as Device Manager.
Last edited by earlan357; Jun 24, 2025 at 05:02 PM.
Reason: spelling
