Z32 Cluster of Problems

[Sushi VII]

On my girlfriends Z32 which is NA and automatic, the lights on the dash come on at once while driving, the alternator isnt charging the battery, the car struggles to maintain a steady rpm when at a stop (unless the car is put into neutral then idles fine at stops), the engine hesitates as if a piston isnt working but then gains power back at higher speeds. If I get the rpms higher then all the dash lights start to go away.

I've already taken off the IAC to clean it out and replaced the gasket, tested the battery charge while running and the voltage gradually goes down, replaced the old worn down battery with a new one, and cleaned off the contact points for the grounds. I havent checked if the alternator belt is loose/slipping yet but I dont hear any belt noise while driving if it were slipping.

I have yet to get to the alternator to test it and to check the belt since its freezing outside and everything on this engine is so cluttered together that it makes any simple job into a long and tiring process.

[everpresentnoob]

well if you can see the battery voltage dropping while its running, your alternator is not working. A slipping belt would still put out some voltage, but a dead alt wont.

have you checked your injectors/coils? while engine is running unplug one cyinder at a time. if the engine speed changes that component was good (mostly, still can follow up with a multi meter test). If there is no change then that component is most likly dead. In my car when I got it is hesitated and had lack of power under 2500rpm. Found that I had one dead injector, and two others that were on teh way out. Got them replaced and it runs great now. Another way to check injectors is to take a long screwdriver and with the car running press the blade of the screwdriver onto the top of each injector while pressing your ear to the handle. there should be a nice steady clicking. no clicking, erratic clicking or other odd noises indicate an injector that is not operating properly.

I would take the car and have the alternator tested first. These cars have an overly complicated electronic system, and if it is not getting the proper voltage it causes all sorts of problems. Most auto parts stores will test it for free.