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.

[swimshark]

well, my J30 idles at 400 rpm at times and it used to shudder (rumble) when it sat at 400 until i replaced the air filter box with a 4" cold air intake. now my car just sits at 400 and i cant even tell if the engine is running at a redlight but the rpms show that it is. on the fact about your alternator, um DUH , your lights are going to dim once your car is off. they are using your battery's energy which is not being recharged by the alternator. its a little bit of common sense if you think about it . and quit worrying about so many things. your car is doing fine. just make some easy changes. i only really know the basics about a car but ive gotten my J30 to perform alot better with the simple low cost enhancements. oh yah and btw, you car should drive fine if you are a normal driver. i push my J30 to the limit almost everyday and she still runs like a dream. had a check up done on it recently and she checks out with a perfect report. 12 yrs old and it still runs like it was new. just worry about things like your tires and make sure to keep your oil changed every 3000 miles (or that is what i do anyways). do this and your car will love you and keep it shape for a good many more years. <-(Bad Grammar)

[supersnake83]

Alright,

Thanks. Maybe I am worrying too much. If you could, post a picture of your cold air intake. I actually took my air filter out to see if it will be a little better on gas, and actually I noticed a little difference. But I use a cheap fram or whatever I can find.

Thanks,

Geoff.

[swimshark]

well my official cold air intake is a 4" air induct pipe with a 4.5" mushroom air filter on the tip in the front bumper where it can suck in some fresh air.




"Car eats bugs from going too fast on the highway."

took me an hour to nibble a circular hole in the panel and about $15 for the pipe and connectors then another $15 for the filter off of ebay. looks and sounds stupid but works well. car performs and sounds better than before.

[supersnake83]

Nice!

Creative and not bad for the money either!

Geoff.

[swimshark]

here is the filter i got. doesnt really mattet the car. http://cgi.ebay.com/ebaymotors/4-5-A...QQcmdZViewItem

[Underground_Killah]

1. check your pcv valve.. it may need to be replaced ( after i replaced mine and my plugs, it idles at 800)

2. That adapter you have on ebay is crap.... don't waste your money

3. the intake you made is ok, however autozone, you get what you pay for.

4. The stock intake is great as is in all honesty.

5. I'd also check your air filter (i have a k+n)