I hooked a pressure guage to the eng. and left it for2 days.press.good.pulled all plugs and ck for spark.all good.the shop where its at ck the inj.pulse.good new.air filter.ck eng.light was on the code was one flash pause 3 flash only code that came up.i have a gm repair man. and went stepby step ,through the troubleshooting of ,eng rotates but wont start.eng. starts but dies. eng stalls.eng.elect. system and fuel system. ive ck and reck. all systems. comp is good.ck.all connections of wireing harness fues pannel and ing switch and wireing.