jhill ha scritto:

 Hi, sure a bad injector, or a clogged fuel filter or fuel pump may
bring to misfiring, but it seems more an ignition problem.

Check and clean well the cam position sensor, then the ignition coil
(which is too close to the engine and may be overheated then cracked),
if this is the real problem you can change the coil with a oem part or
with a single coil ignition (see it on sale on ebay).
Ignition is critical, and a symptom is also bad idle speed when air
conditioner or lights are on.

What is the situation when the engine is hot? You might have also a
leaking of oil from the head gasket..

Just to give some ideas, check them and revert.
andrea

Dumb question - did you disconnect the battery before changing the starter?
Did you spark the battry cables bad?  If you did, you have blown your ecu.