Chevrolet Repair: no spark, crank sensor, chevy van

Question
I've just installed a rebuilt engine in a 99 chevy van 3500. well to start after everything was installed i forgot the plate in front of the timing chain behind the cover.wich then i reinstalled and replaced the crank sensor cause we believed it could have gone bad. after that we still had no spark we've then replace the coil, distributor, and also has complete new set of wires,spark plugs and cap. but still no spark.

Answer
you may have to learn the new crank sensor. in those years, some you had to learn if you replaced it, or realearn if the battery went dead. my best advice here is try that. call the dealer, and see if there is a relearn procedure for that. if its not learned, you wont get spark becuase the computer doesnt know what cylinder or stroke the engine is on, so it wont let it start. that way no damage can be done.