WELCOME!
I am hoping for two things right off the bat. 1) I hope you didnt buy a map sensor because a 94 wouldnt have one OR 2) you have a 93 and you really do have a map sensor.
It wouldnt be a dead spot on the TPS because that would do it all the time and not just at one speed. because you have a code for unusual injector voltage, just check the wiring around the injectors for any signs of damage. burned or melted wire insulation could cause it to ground out every now and again. check that and check simple stuff like plug wires and plugs.
Mike would probably know better than I would though, try asking him (forum name: 9secfirebird)