The injector gets activated by its PCM output driver getting pulled to ground. Check to see if that's happening (PCM connector not fully mated, bad wire, PCM output bad).
The engine not rev'ing over 2500 rpm always points to a bad cam position sensor (because the timing is controlled by the crank pos. sensor up to 2500 rpm, then goes to the cam pos. sensor). So bad sensor or bad connection.
Hmm. Two things run by the PCM not working right. First check for complete mating of PCM connectors, then on to other causes if no joy. If PCM connector (or bad PCM) not the problem, very likely two unrelated causes of injector and no rev. above 2500 rpm.
Get cam pos. sensor OEM from dealer only (aftermarket ones are generally unreliable - sometimes right out of the box). Not a bad idea to replace both cam and crank sensors at same time (both from dealer only).
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs