It's been a while since I had time to tinker with the truck, but the latest update is that I did re-verify that I have spark right at the plugs. Every plug was wet from fuel, so the high fuel pressure may be flooding the engine and preventing it from starting? I forgot to turn the engine to TDC and check the rotor position to try to see if the timing belt skipped a tooth, but I'll do that next.

In any case, I dove into replacing the fuel pressure regulator since I didn't see any obvious signs of a problem with the return line. I thought I could sneak it past the manifold, but no luck - so the intake manifold is off along with many other things while I go get some new hoses and gaskets.

Question - when I removed the EGR tube from the intake, I found that it was oily. I also found a small amount of oil before the throttle plate. It looks like some oil has been coming into the air intake from drivers side valve cover (a guess, but that hose is somewhat oily). Could this just be from the engine mis-firing or plain not starting, or should I be digging further into this while I have the manifold off?