so I bought two zc (actually 1.6i-16) crxs. one of them has some problems when Im accelerating, it kind of stumbles almost like the timing is off, or it needs plugs or something. when I get up in the rpm range (3k to 4k) it seams ok. then when Im crusing it comes back. just wondering what I might could do to fix it. im going to check the plugs out and mess with the timing a little, see what I can do. thanks

 

Come back reporting on plugs first step you sound like you have a strong guess.

 

check fuel injectors

 

Can't be the injectors, if that were the case his car would have been sputtering all the time. It can mean 3 things:
1: wrong ecu
2: like Capt. said it can be sparkplugs
3: check the sparkplug seals on the head, make sure no oil is leaking into the sparkplug chamber. If sparkplug has oil on it, means you need new ones.
The last should just be timing...

Had the same problem, when I reved btwn 2k-3.5k it sputterd and ran smooth over that. When cruized it came back.

Op: use brake cleaner to wipe off all excess oil from the plug, makes it clean and quick.