95LTXZ28

iTrader: (19)

Ok guys awhile ago I put on an underdriven alternator pulley to keep my voltage up in conjunction with the underdrive crank pulley that was on the car when I purchased it. The voltage ( on the dash gauge) was reading a little over the first slash so I'm guessing around 11.5- 12 volts. I recently installed an Msd 6al2 using the Msd coil harness to simplify the install. Now sometimes the cars voltage at idle dips below that slash and almost reaches the red section on the voltage gauge. I've also been noticing a shuttering when cruising under partial throttle, almost like a miss. Is my battery on it's way out or should I ditch the whole under drive setup and run the stock balancer and alternator pulley instead of the piggyback crank pulley. Or should I unplug the msd box and see of the problem persists.

quik95lt1

iTrader: (7)

the msd will run down to around 10 volts so idk if thats it......also the ecm needs about the same to run...........so im not sure if thats your issue......

95LTXZ28

iTrader: (19)

Ok ill have to check else where it seems that it started after the Msd box install, maybe a fluke though

96blackz28

iTrader: (3)

I had voltage issues with an underdrive pulley kit, but turned out my junction block (the red box on passangers side) was so corroded and rusted, once I replaced that I had full power and no voltage issues, also my hvac fan actually ran way faster as well. Just something you may want to check out. I know when my voltage dropped the car would not run well, if i gunned it it would backfire real bad after letting off throttle

I know you are running an MSD box, im not sure how much juice that takes to operate, but i would check the voltage coming from your alternator wire with a multimeter and also could be a weak battery.

I wouldnt say your underdrive kit is causing you issues, my car is fine now, it just turned out to be something else that was a weak link.

Big Al

iTrader: (1)

One thing for sure, it's not a weak battery symptom. If the battery is starting the car, and if it really has low voltage, it's a charging system problem.

Al 95 Z28

mattj21

Have anyway to get a multimeter? If so id go ahead and start some voltage drop testing on the alternator, fuse box, etc.. just go along and use process of elimination

95LTXZ28

iTrader: (19)

Ok guys I'll check everything with the multimeter. Would low voltage like that cause a shudder when driving though?