Today I was going down the highway and the car started jerking and hesitating. While it was doing this the rpms would go to 0 then back to normal. Finaly it stalled. Then ,when I restarted it, the car had a check engine light on. When I scaned it I got a code 42 EST spark problem. What do I need to check or change to fix this?
Thanks
Shawn

Check distributor wiring, including grounds. Check the EST connector and knock sensor connection. If that doesn't resolve hte problem, open the distributor and check the connections at the HEI switching module. You should also test the pickup coil resistance and reluctor condition while you're in there.