Got my new IROC-Z today, and drove the 330 miles home. Car acted fine the whole way... nice oil and volts(14 most of the way) temp a little low, but its like 2 degrees outside. After dinner at Ruby Tuesday's, leaving the lot with the lights on my voltage gadge was having a fit. It would pull down low... lights dimming, then jump up, lights back up, and do this again and again. Only at lower engine rpms, mainly under 1500rpm, and more so when lightly accelerating, and with heat on. Whats up here? Voltage regulator? The alt looks new, belts not slipping. I also noticed that at a WOT pull, there was a small, but deffinatly noticeable studder around 3000 rpm. Seems like electrical... happens very briefly, and goes away, not gets worese as the revs climb. Tried this a few times... both in second, and thrid. (No way in first... can't do much WOT there... it really goes!) Any ideas on whats going on here. It seems like the alt... to me anyways... I hope you guys can set me straight. Tomorrow we'll see what it does without lights and heat needed. Thanks in advance.

 

Funny, I have the exact same car, engine size, color and all and I have the exact same problem. I just bought a new hi amp alternator as well and the problem still exists. I have read some other posts that said you have to upgrade the power wire and ground wire coming from the alternator to the battery when upgrading the alternator. I am going to do that sometime this weekend and see what happens. Hope it helps! Good luck.