Hi!
We pulled in a 305 tpi speed density engine in a astro whith a painless wiring.
I canot get rid of the code 43 and 42,we change alot of things,esc,ecm,and more,the car runs fine but just on the rich side.
The problem is that i canot read the ecm by datamaster the DTC is red and the connection are comming on and off all the time.
Any clue?
Thanks!

 

Speed Density doesent use ESC its on the Memcal on SD setups, did you change the Memcal? or do you have a ESC?

Code 43 is ESC error so does the car have a ESC unit ot is it a Speed Density setup?

Code 42 is EST error, check so that the brown/white Wire from the dizzy is connected.

Go to www.chevythunder.com there you will find flowcharts of the error codes. "troubleshooting flowchart link"

/N.

 

check the knock sensor and the wire harness to it. the knock sensor should have about 3500 ohms resistance when checked from terminal on sensor to ground. if it is open or less then 3500 replace the knock sensor. if it reads correctly check the harness