Need code # 42 help...

[Madmustard]

Had a recent no start problem...Changed the ignition module and coil.still no start..swapped out to a different computer that I got with the gn..started right up but seems to sound different and a lower slower idle...and have had a code 42 and engine light on ever since...Tried 3 different coils and ign modules...these are kirban and or new units...

code 42 on scanmaster also says ground or bad wiring...how am i going to be able to tell whats bad where?
where is the ground for this code?all grounds i find appear fine and are grounded...
what is the est circuit?HELP!

 

[87-WE2]

I'm having this problem also. I did a little research yesterday and it could be related to bad plug wires, or a poorly connecting pin in the ECM or ign. module. Unplug the ECM & check all the pins and the corresponding females, clean all, and then try them again. This from research on Vortex Buick (Steve Wood's site), and advice from TuboDave on here. I was able to find out that when the code 42 is thrown, the spark timing is no longer controlled by the ECM; the ignition module takes over so that would be the source of your slower idle / different sound. It's also possible that one of the wired from ECM to Ign mod. might be damaged which would cause the problem.

Search "code" on here & you should find some info for things to check besides grounds.

EST = Electronic Spark Timing circuit.