[T77911S]

replace the plugs as i said. they can foul
then check spark at the plug.
go ahead and lift the sensor plate with the key on and then give it a start. ( a quick check of the CSV system).
there may be voltage at the CSV, but it could still be bad. if it fires up with the above, dive back into it, if not, back up and punt.

if the CSV circuit is working, usually you will get a a quick fire and it will run for about a second or 2 then shut off and not fire again.
if it does not fire at all, look to the CSV or ignition.
also, if you have had the dist out, recheck it. make sure you are not 180 out (usually you get loud backfires) or off by several teeth. you may have fixed one problem and created another.

one other thing you can do is have someone else start it while you lift the sensor plate, or pull it down. ( if for some reason the mixture is way off, this is a crude, non permanent way to compensate). lifting up makes it run richer, down equals leaner.

this is a more or less if all else fails order.

dont forget air leaks.
do you, well your car, have a pop off valve? check to make sure it is seated properly. they can open and not close all the way.