Weird Idle Problems

[Doya]

When my car is idling, after it has warmed up to normal operating temperatures, it will drop down to like 600-750 for a few seconds and then go back to like 900. It drops really low when I turn my headlights on too. Anyone know what the problem could be? Thanks

[YuNg1's_240sx]

Hey I have the same problem. Do you have any leaks? I believe the oil leak is going to my alternator and messing with the connection. Does your rpm also drop when you have the clutch depressed and you are slowing down?-Arash

[Doya]

Actually, I think my front main seal might be going bad. Could that be the problem?

[del82]

Since the alternator electronics are coated, that'd be a no. It would be a problem if every time the alt. got wet it stopped working, yeah? heh...

Most likely its not even a problem. The idle will move around a bit when the A/C compressor kicks on, or when a large amp draw is placed on the alternator, since it momentarily outpaces the IAC motor's ability to control the idle. If you're really concerned about it, you can pull off the IAC motor and clean the port and the plunger. I don't think you'll see a huge difference though.

[YuNg1's_240sx]

but the thing is, my car was fine before the leak... when the leak started and spitting out the oil, i think it messed something up inside there. but this is just my guess for my car. When this happens the lights dim and there is a big click. It get's pretty annoying after a while.

[YuNg1's_240sx]

Actually, I think my front main seal might be going bad. Could that be the problem?

I think it might be, because I am having the same kind of issue. Did yours do this before at any point?

[YuNg1's_240sx]

Could it be grounding issue also?

[Doya]

I think it might be, because I am having the same kind of issue. Did yours do this before at any point?

My car has done this ever since I have had it. I was only worried about it because whenever I go to take off with my lights on, it kind of struggles to get past 1500rpms. I don't know if I mentioned this early, but when my lights are on, it will stay idling around 600, unless I turn off my lights.

[YuNg1's_240sx]

whereabouts in MD are you? maybe we I can see if we have the same problem or not.

[Valett85]

Ok. So when your car reaches normal temp your rpms drop? Is it possible that your secondary fan kicks on at running temp? i honestly don"t know. they also drop when you turn on your headlights? I'm guessing it is your alternator. It is obviously electrical. your car can"t hold up to the ampere load you are putting on it. if it isn"t your alternator i would look into a new battery or better grounding. check for a lot of corrosion around your terminals.

[Doya]

whereabouts in MD are you? maybe we I can see if we have the same problem or not.

I'm in southern maryland, we will have to meet up one time once I'm done with the turbo

[Doya]

Ok. So when your car reaches normal temp your rpms drop? Is it possible that your secondary fan kicks on at running temp? i honestly don"t know. they also drop when you turn on your headlights? I'm guessing it is your alternator. It is obviously electrical. your car can"t hold up to the ampere load you are putting on it. if it isn"t your alternator i would look into a new battery or better grounding. check for a lot of corrosion around your terminals.

I'm pretty sure that it is an electrical problem, and yes, I do have alot of corrosion around my terminals. The battery is new, and I know my alt. is good, so it most likely is my ground.

[YuNg1's_240sx]

hey did you ever get this fixed? im going to look into it more this weekend.-Arash

[Doya]

hey did you ever get this fixed? im going to look into it more this weekend.-Arash

I got a OHMs meter and I'm going to check my ground this weekend. If it shows any resistance, then you have a bad ground.

[YuNg1's_240sx]

Do you think we can meet up sometime and check mine also?

[VMP]

check the grounds from the block/head/trans to the chassis. a tiny amount of resistance is okay. but if it's excessive, then you can try cleaning it, or replacing the whole wire itself.

However i wouldn't blame something like that simply on a bad ground. Check the amperage output of your alternator and also check the voltage on the battery while the car is running. make sure it's around 13.5v and 14.5v.

Also, is your check engine light on?

[YuNg1's_240sx]

yea, my CEL is on. i havent gotten a chance to get the reading for it though.

[YuNg1's_240sx]

hey is there anytime this week or weekend that i can borrow the ohm meter?