Replaced Valve Cover Gaskets Now Misfires?

[ImWorkingOnIt]

I have a 2001 Mazda B3000 that was running properly before I replaced the valve cover gaskets to address a minor oil leak. The repair itself appeared straightforward and was completed without issue, but afterward the engine will no longer start. It stumbles during cranking as if it has a severe misfire.

Since then, I have checked for vacuum leaks, including using starter fluid around the plenum gasket while attempting to start. I’ve verified the spark plug wires are correctly routed on the coil pack, confirmed injector pulse with a noid light, and verified spark at all cylinders. Despite these checks, the engine still will not start, and I have not been able to identify what may have gone wrong during the repair.

Anyone have any suggestions? Appreciate any help

PS: valve cover gasket replacement involves removing intake plenum, coil pack and a bunch of other EGR vacuum lines ect. I checked to the best of my ability that everything is plugged in correctly.

 

[Angie]

all i can add is you need to retrace your steps. something is a miss when you put it back together from the sounds of it. did a rubber vaccuum plug fall off a nipple?