Alternator problems...

[Bullitt66]

Hi, i just hitted a wall, don't know what to do next, my car is a 96 Cobra that had a bad alternator, I replaced it 2 days ago along with another ground to the engine and it felt better, problem is volts go from 13v to 11v when the engine gets hot, since it had underdrive pulleys, and it also has temp problem (overheating) I put the stock crank and water pump pulleys, but I don´t have the stock alt. pulley, so I leaved the one that came with my new alternator (same size of the underdrive kit). So now the car was making 14.14v when cold at idle, I reved my cobra to 6000 and battery light came on and volt gauge went from MA to O in "NORMAL", changed the new regulator with the old one and battery light is still on, and not charging, Checked fuses and everything is ok, what could be wrong? did I override the alternator burning something? what size is the stock alt pulley?

Thanks

 

[006]

I think your stock one might be 2.45-2.48" at the outer lips.

Measure the diameter from lip to lip (edge to edge), and let us know.

 

[Bullitt66]

Update: I put the old regulator on the new alternator and the battery light didn't turn off, so I put the old regulator on the old alternator and the light did turn off, so then I put the UD cranshaft pulley, Did I fryed the diodes for overspining the alternator or something? Volts still go down to O of Normal in the gauge, about 12.2V...

On the other hand, I have a problem about my car not reving like it should, today I couldn't drive it, but when I disconnected the Maf sensor, car ran great at wot like it did before, but off course, it stumbles at part thottle, how do i test if my maf is ok? is the stock one, and last question, does the ecm ignores the O2 readings when the maf is disconnected??? I have no codes when everything is connected, at least I know that the problem is not my coil packs (stock ford) or wires (jba)

 

[Bullitt66]

If I don't have any codes, it can't be the maf or o2 sensors, so it should be an exahust leak from the headers right?