98 ranger misses at stop light

[lomchivok]

then clears up a few seconds then misses again. when the light turns green and I give it gas it wants to bog...let off the gas and give it some more and it ...kind of clears up. Power has been way down for over a year as I have thrown nearly all new sensors, modules, coil packs, plugs, wires, injectors fuel filters and pump, intake gaskets etc etc etc at it. Compression checks out good @ +- 5 psi @ 150 on all cylinders 309000 miles. I get random misfire codes, misfire cyl 1, misfire cyl 4, misfire cyl 3, misfire cyl 6 etc at different times. I think next is the ECM compuketer...but first there is one thing I have been looking at and can't figure out what it is or what it does It is shown on a drawing here

http://XXX.justanswer.com/ford/2gmek-1998-ranger-4x4-4-0l-starts-stalls-seconds.html

as C124. It has a large bundle of wires attached to it in a block held on by a screw that comes from the firewall under the master cyl the other side has another large bundle of wires coming out and goes to the ECU in the upper passenger side firewall. Is this some kind of control module of sorts or just a junction kind of way to route wires. it is held in place by a clip just above and back from the EGR diaphragm and behind the Differential Pressure switch...at my whits end on this one. Yah I know...I should have just gone in to the dealer an had em scope it out...but I haven't yet...so here I am.