Rebuilt Engine Codes 42, 43 and Stalling

[bocoogto]

Since the rebuilt engine was put in my '93 two weeks ago, I've had two separate problems with engine management.

First, the Service Engine Soon light came on several times upon acceleration from a stop. Checked and noted codes 42, 43, which show spark knock sensor or timing problems. I checked timing and saw it was about 7 degrees advanced. I corrected it to zero degrees by disabling the EST and turning the distributor.

After that, the engine quit three times immediately after startup. When trying to restart, it acts like it's flooded. After quite a lot of attempts, the engine started and ran each time, but roughly at first, with strong gas odor. Service Engine Soon light stayed on each time until shut down and restart. What could this be?

I've noticed for a year now that the engine must be turned over quite a lot after sitting overnight before it fires. Could there be a check valve in the injector circuit failing--possible related to the new stalling problem?