Idle stumbles when headlights turned on

[vancouverbc]

Idle seems ok otherwise. Could this be a weak battery or alternator? I know the FICD comes on for air conditioning. Not sure what other times it comes on or why it exists when there is an aac valve.

[tiger]

probably a weak alternator.

[BreedOfSpawn]

I got the same problem Vancouverbc seems like its starting to happen to you now 2... Its getting tooled up tomorrow by a mechanic who happens to be a friend as soon as I find out whats causing it I shall let you know. I have a suspitition that the alternater is a P.O.S cuz its really old.

[Q45tech]

Visualize that alternators have 3 circuits in parallel..........common for the weakest diode to blow open reducing peak capacity by 1/3 or 2/3 prior to total failure.

ECU controls IAC to maintain idle [tries to maintain a set voltage at ecu also]...........compensates for voltage drops, PS, AC loads.

IAC duty cycle [10-20%] vs manual bypass air must be just right to give it enough dynamic range.

Above is generic for all Nissan/Infiniti engines.

[vancouverbc]

Ok, sounds like an weak alternator. I hope the ficd is kicking in to help the acc .

[BreedOfSpawn]

Let me know vancouverbc if it fixes the problem cuz then that means I also need a new alty... not an expense im ready for but Will get done if needed.

[vancouverbc]

It was a hypothetical question. If its the original alternator, I would replace it when you have the money because it is about time for it to go. same with starter.