Chevrolet Repair: 89 firebird, poor connections, inj

Question
ihave an 89 firebird, 3.1, that won't start.  it has spark, has fuel pressure, went to check pulsating current at injector, unplugged injector , car fired up, runs on 5 cyl.  won't start with all injectors plugged in.. any ideas?? thanks

Answer
Hi Eric... check for short to ground in the wiring for the inj you have unplugged. put a voltmeter across the term of that inj and check for continuity... if thats all ok then check the ign module. check for inj referance on all cyls. if ok there check the PCM. make sure you don't have any bad wires or poor connections... check all connections for corrosion bridging....thats where the corrosion is built up enough to bridge several connections together causing a short.... hope this helps