Any reasons why my Idle is so Low!!

[supersnake83]

Hi everyone,

For some reason, my idle drops down to about 300 rpm's when I am in drive and stopped at a light. I had this problem before when I had a bad alternator, but I changed my alternator with an OEM alternator rebuilt.

I checked the factory service manual and it states that when in nuetral, the idle should be at 720 +- 50 rpms. For my car, when in nuetral it hovers between 450 and 500. Is this too low?

And is my idle too low when I am in drive/stopped at a light? When it drops, my car gets a little rough (it seems like the car is fighting to not let the idle drop so low).

Also, I have noticed that my headlights lights dim if I leave them on and shut the car off. I don't know if this is normal to save battey consumption or if this is a power problem.

I did notice however that my alternator is putting out about 13.5 volts. The FSM states that that is fine as long as the voltage does not get higher than 15.0 volts.

Help if you can. I am thinking it could be something air related, but afte the headligts dimmed a little after the car was turned off, I am now thinking that it could be something power related.

Thanks everyone,

Geoff.

[yodawill2000]

Have the Battery checked ??

[supersnake83]

Hi everyone,

Thanks for the replys. Actually, my idle hovers around 900 rpm when in park/nuetral and about 600-700 rpm when in drive/stopped. I was thinking of a clock instead of an odometer when I posted this thread. Sorry.

I believe that that idle in drive/stopped is normal. It is just a little crazy sometimes when it tries to go below the 600 rpm mark. That is when it feels like the engine is fighting to stay at a higher rpm. Is this normal?

Is the nuetral/park a little high? Does this mean that the car is running too rich or since the idle is normal when in drive, is everything o.k?

Thanks everyone, and sorry for the clock/odometer mixup.

Geoff.

[redboeing]

I suggest cleaning the throttle bodies. It's easy to do and if it does not cure the problem, you know you have eliminated one of the possibilities.

[Nissansbitch]

Don't overlook the timing belt and tensioner.