engine miss after warming up

[partsmanctc]

I have a 98 grand cherokee 4.0l engine,the engine misses after warming up,the miss was worse before i installed new plugs,wires,dist.cap/button driving and under load it seems fine,any suggestions.i also have to install new track bar but the lower mounting bracket on the passenger side axle in non existant,can this bracket be purchased from a dealer if not can it be made and welded into place,is there specs that can be followed to make this bracket

[hardisk_c]

If it's only doing this idle-warm then I wonder if the IAC and/or throttle body might benefit from a cleaning. . . time to break out the carb cleaner!