90 lumina OBDI code 42

I have a 90 lumina w/T eng. code, W is the fourth in the vin. so this thing runs really rough, stumbles bad on acceleration, has had a lot of work done to it recently, rewired and replaced the crank sensor. the fuel pressure is a steady 37-42psi it also has new coils and ICM. this code is so vague I am currently going to start at the beginning and check for cracked plugs, loose or mixed wires and the wireing to and from the ICM. I would like to know if I have overlooked anything or just plain forgot something. please advise. looking for richtazz

code 42 is an EST (Electronic Spark Timing) signal code. Here is a link to an article that explains what it means, as it has multiple definitions and causes. I hope this answers your question.


http://www.troublecodes.net/articles/gmmsundrstd42.shtml

I thank you for the link help will try to figger this thing out and let you know.