Patience grasshopper. /forums/images/graemlins/ignore.gif Both of my TBI (transplants) have been running great since I got the bugs out of them, even on the vortec heads.
You might even just pull the control module out, and have Autozone test it for you. If its good, you can eliminate that option. SECOND, run a 14ga or larger ground wire, from the engine to the ECM case. Often times, bad ground can cause this problem too. I've got this same wire on my setup. FINALLY, if your problems persist, do you have a spare ECM that you can test out in place of the one you are currently running? I've heard of code 42s when the ECM goes bad too... /forums/images/graemlins/blush.gif
Here is how to adjust your timing PROPERLY:
1. Start engine, and allow it to warm up. Make sure the SES light isn't lit and that there are no codes stored.
2. Disconnect the brown-wire barrel plug.
3. Try to get the idle down to 600-700RPM.
4. Connect timing light to cylinder #1, and adjust timing to desired base timing. A good range is from 4-10 degrees BTDC. I run my engine at 8* with great mileage and good power in my Burb with vortec heads, stock cam, stock exhaust, and an edelbrock intake.
5. Tighten distributor, and check timing one last time. If its still set where you wanted it set, shut down the engine, disconnect the timing light, and reconnect the brown-wire barrel plug.
6. Disconnect the battery for 30 seconds to clear any codes, and then reconnect.
7. Crank the engine, it should start quickly and idle properly without any SES lights.
Did you ever adjust the IAC motor for minimum idle speed? How about checking the TPS voltage? These are important too for a vehicle that has had a TBI transplanted. Let me know if you want directions for these processes as well.
Additionally, see below for more info on code 42:
<font color="red">42: Open or short on EST or BYPASS line to ignition module; ECM timing signals not getting to ignition module - A disconnected timing connector will cause this code as will a bad ignition module</font>
For info on the ignition module wiring see
HERE!
I hope THIS info helps... /forums/images/graemlins/cool.gif If nothing else, send me a PM and I'll drop you my cell #. /forums/images/graemlins/grin.gif
-Dan