1996 olds 88lss. My egr valve melted and allowed coolant in my air intake. I replaced the plastic upper intake manifold and egr valve and its spacer sleeve. Put everything back together and engine won’t start now. I have compression, spark, and fuel. Replaced ignition module and crank position sensor and still no combustion. Plugs, wires, ignition module, compression, fuel pressure, injector resistance, crank position sensor, new battery.
When you had all the plugs out, did you happen to crank the engine to blow out any coolant that may heave gotten into the cylinders?
Other than that, go back through, and make sure you’ve reconnected everything correctly. Did the engine light come on at all after the EGR failure?