I've been starting the heroic runs recently, never ran into any major problems, but there's one mob that's been giving me a lot of trouble - Mr Abomination and family.
Everybody's favorite plastic surgery nightmare seems to think i'm a mushroom and keeps hitting for 4/6k. Our guild healer told me that I'm the only one he has so much trouble keeping up, he also runs this heroic with 2 or 3 other warrior tanks in similar gear and talent specs but without the spike damage... If that's what it is...
I think I had some similar troubles myself. You sound like it's about the same, but here's a few suggestions.
CCing a crypt fiend or ghoul can help a lot if you've got a priest. What I found was that an Abom alone wasn't too bad. An Abom with a ghoul was doable, but an Abom, 2 ghouls, and a crypt fiend was a run back unless I had shield wall off cooldown. Heroic Culling is not vary forgiving as far as tank gearing is concerned.
Get your debuffs up quick. It's annoying that maybe your DPS has to wait an extra GCD for you to get your demo shout up to go with the TC, but those debuffs really do go a long way from 100 hp overkill to surviving with 200 health and the healer nails you with a 16k crit.
Everything else is really just make sure you are using your shorter cooldowns liberally (i.e. Shield Block and Trinkets).
There is really not much you can do you can have the healer priest shackle some of the mobs like the spider. The ghouls alone hit fairly hard once they frenzy so try to keep them stunned as long as possible along with your dps doing whatever they get to keep damage off you such as a ret pally stunning or a mage blast waving to frost nova anything at all helps. Its basically and focus fire until your gear is improved.
For Abom pulls in there, I usually charge the abom for a stun, TC/Demo shout ASAP on the group, then shockwave, once that stun is off pop a dodge trinket. As soon as my dodge trinket is off CD, I concussion blow the abom and my dps should have it dead by then... if not another shockwave stun usually does it. If you keep the stuns tight, it gets at most 3-4 swings at you -- and stunning the ghouls with shockwave doesn't hurt either.