Lilac bushes did not leaf or flower this year

Help! Last year my three (in a row) lilac bushes did not get very many leaves or very large flowers...But this year they did not leaf or flower at all. Last fall I pruned out some dead shoots and small branches. I also trimmed a very few live ends. I know that it is better to prune in spring after bloom, but health issues prevented doing it then. Was it the fall pruning that has caused them to not produce any foliage or flowers this spring? I do not think they are actually dead yet... But I also do not want them to die! What can I do? Is there any hope for them? (Location is Colorado front range.)

It's worth giving them a little more time to see if they'll leaf out for you, but if they don't get any leaves on them this year at all unfortunately I think you'll need to give up on them. Sounds like they weren't very healthy last year either so they were probably already on their way down then. Fall pruning can prevent you from getting flowers, but it wouldn't prevent leaves from growing.

Thanks ecrane3! That was my biggest worry...whether the fall pruning had killed them. I will give them some more time as you suggest. So sad because they are actually pretty big bushes. I don't know how old they are, but they were well established (although neglected) before we moved here 4 years ago. But it does seem like their blooms have become more sparse over that time.
Any more ideas out there? Does anyone know of a particular type fertilizer or plant food or anything that I might try while we ride out the summer?

I am not an expert, but my mother in law cut hers to the ground one fall and the next year it thrived. It seems drastic to me, but if you do not see any new leaves, it wouldn't hurt to try.

I'm not sure if links are acceptable to post here, so I just copied what you might need about fertilizing.

I found this blurb at Yahoo answers:

Lilacs like slightly "sweet" soil so a good sprinkle of lime and a gentle dose of fertilizer will certainly help the cause!

I only clip out dead flowers post bloom (labourous task) to direct nutrients to the lilac plants not to the developing fruit. I also remove any obvious dead branches in early spring before buds swell. If you prune twig tips you will be removing next years flower buds (assuming you some variety of the standard lilac - Syringa vulgaris). I've never fertilized my 3 bushes - my philosophy is that if the lilacs are too happy then why would they need to flower. Good luck, keep us updated as to their progress. R

I would add a feed now that you have already cut it way back, it probably just needs time to recover from the shock of drastic cutting, it might take a couple of years to recover, the best way to find IF the branches are still alive is to hold the branch between finger and thumb, gently rub away a small bit of branch with thumb nail and if the wound looks brown it is probably dead, if White or green, it is alive. fork in the feed around the root area gently not to cut the roots, make sure it gets plenty water to help swell up any new buds it is trying to form for next year, also at the same time it will be trying to make new leaves, so it has a lot of catching up to do, if you feed it now, come next spring give it another feed, so it gets a good start to help flowering, don't over feed, just give by directions on packet, maybe a mulch of nice new compost around the roots would help too especially IF the shrubs are older ones.
Good luck, hope it all works out for you. WeeNel.

Something I forgot to ask - are your plants getting lots of direct sunlight? At least 6 hours per day should be fine I suspect. Good luck.