old thread follow-up...
ok...it's been several months since I posted in this thread and I've made some progress so I figured I'd post an update...
Finally got the popping and misfire underboost solved and taken care of - turned out to be the plug wires!!!
Yeah, I feel pretty stupid about that, but the wires were new when the problem started. I recently installed a set of Magnacore wires and the problem dissappeared. *However* within 40 miles of installing the new wires, the ignition module died. 
I have installed a new Delco ignition module and the car seems to be running fine although I still have two secondary problems that I *expected* to dissappear with the original popping and misire....
1. When the cooling fans turn on, the engine will either stumble or die completely. If it dies, I can restart it immediately with no issues.
2. If the A/C is on and you change the fan speed (hi-med-lo) the engne will stumble or die. Again, if it dies, I can restart it immediately with no issues.
I thought the above problems were possibly caused by a failing alternator so I replaced the alternator - no improvement, engine still stumbles or dies with the cooling fans or A/C fan speed change. When either of these events occur the tach. needle jumps around. I'm running the G-BodyParts dual fans with the Casper's fan harness. Anyone have any idea why my engine stubles or dies with the cooling fan or A/C blower fan?
Thanks,
Rob
ok...it's been several months since I posted in this thread and I've made some progress so I figured I'd post an update...
Finally got the popping and misfire underboost solved and taken care of - turned out to be the plug wires!!!
Yeah, I feel pretty stupid about that, but the wires were new when the problem started. I recently installed a set of Magnacore wires and the problem dissappeared. *However* within 40 miles of installing the new wires, the ignition module died. I have installed a new Delco ignition module and the car seems to be running fine although I still have two secondary problems that I *expected* to dissappear with the original popping and misire....1. When the cooling fans turn on, the engine will either stumble or die completely. If it dies, I can restart it immediately with no issues.
2. If the A/C is on and you change the fan speed (hi-med-lo) the engne will stumble or die. Again, if it dies, I can restart it immediately with no issues.
I thought the above problems were possibly caused by a failing alternator so I replaced the alternator - no improvement, engine still stumbles or dies with the cooling fans or A/C fan speed change. When either of these events occur the tach. needle jumps around. I'm running the G-BodyParts dual fans with the Casper's fan harness. Anyone have any idea why my engine stubles or dies with the cooling fan or A/C blower fan?
Thanks,
Rob
