no fire at the coils on my envoy
my envoy will not start from time to time I check and has no fire at coil packs, a hot 12 volts with ign on then all the sudden it gets fire and starts have replaced ign switch,map sensor,oilpressure switch.this thing will die and wont start for an hour then fir e up and go.has 12 volts at crankshaft sensor on ign but not at coils.bumfuzzled



