Running great then died, now no start

[DaveRT]

New here and to Sienna's but not to car repair. Been DIYing for 40 years.
A bit of background...
A buddy got an unbeliveable deal on a "00 Sienna LE. It had been sitting for a year with a very minor problem. Fixed that and it ran great. Cleaned it in & out, including pressure washing the engine (engine running). Changed filter and oil and the next day took it for emissions inspection. It passed with flying colors - still running great, no codes or CEL. Get it home and it starts to run poorly, rough idle and "chugging". He manages to get a code scanner on it and it shows multiple misfirings and a couple other sensor codes that he does not remember clearly. Soon after the engine died and has not restarted since.
It spins over and sometimes tries to fire but will not catch and run.
We have checked that there is fuel at the rail. Don't have an exact pressure but it appears to be quite strong. have checked the spark with a tester and it appears that we have spark but not sure of strength or regularity. We ahve checked all of the fuses and relays. We have checked all of the wiring connectors we can see/reach for a firm cinnection and to be sure they are not water logged. We have cleaned the throttle body and IAC (new IAC gasket). We have checked the Cam sensor and it is within range per the Haynes manuel. We have not checked the Crank sensor yet. Scanner connected during start attempts show the tps is working and no codes (either stored or while cranking).
Still spins, tries to fire but no start.
What am I missing? I'm quickly running out of ideas.
Please, any help or suggestions are very welcome.

[chuck's sienna]

I never would have pressure washed an engine running or not. Regardless, check the timing belt. You have to have compression, correct time, fuel, air and spark.

[DaveRT]

I've power washed engines for years and never a single issue. And I don't think it's the cause now either but I do understand the concern.
I have not checked the compression yet but symptoms the van had don't really lead me in that direction. I will put a guage on it though, just to be sure.
As for the timing belt, I had wondered about that and have had someone else suggest that too. The van has 118k and I do not believe it has ever had a new timing belt.
Is there any way to check if the belt has jumped a tooth? An access port or some other way to verify the timing?

[DaveRT]

Thought I'd post an update incase any one finds this post in the future.
The van is now running and running well.
The cure? It was as simple as new plugs and wires. No coils were replaced, just the wires to the rear three plugs and all 6 plugs.
The old plugs were pretty bad but I never would have thought that they alone would have been the cause of this no-start issue. But it's been starting and running well for 2 days now.
If there are any new developments I'll post back but, for now, my friend is one happy camper.