dsm_1320

I have a 2001 Z/28 A4 with 98,000 mi. The problem is when I start it and put it in gear it won't take gas. It kinda acts like its loading up it just stumbles and bucks then all at once it takes off. It does this every time I start it up hot or cold but after it takes gas it acts fine. The car is completly stock except for someone cut off the secondary cat. The only other problem the car has is charging system fluxuates at idle you can watch the volt meter bounce back and forth about a hands width you can also see it when the headlights are on they go bright and dim rapidly. I thought the fuel pump might be getting bad or the fuel filter or maybe the TPS could be the problem. This is the first LS1 car I have owned so I'm not sure where to start. If anyone has had this problem before any advise would be greatly appreciated so thanks in advance.

Old Geezer

iTrader: (3)

1. Go thru all the grounds, clean the connectors, check the alt output, have the batt tested..Completely eliminate the electrical gremins FIRST. Until U do, you are "pounding sand in a rat hole".
A complete tuneup is in order. Plugs, wires, fuel filter, etc.
2. Have the system scanned and datalogged. This will allow reviews of wtf is going on when the problem[s] occur.

dsm_1320

I have checked the grounds and battery terminals. The battery is new but I went ahead and tested it anyway and it's good. I'm going to have the alternator tested also but I've not had a chance yet. Do you know if the voltage regulator is built in to the alternator or is it controlled by the ecm? As far as the tune up it was done less than 8000 miles ago.