Fluctuating idle, could it be the alternator?
09-22-03, 05:31 AM
#1
Call me gramps!
Thread Starter
Fluctuating idle, could it be the alternator?
Well, my car's idle will bounce up and down ever-so slightly, but once I hold the brakes, it'll stay totally still. Also, when I press the brakes, the interior lights (if they're on) will dim a little. I suspect it's the alternator, but could it be something else?
09-23-03, 05:04 PM
#4
5yr member, joined 2001
Most autoparts stores will test your alternator for free. I don't think the alternator is your problem, but if you get it tested, then you can know almost for sure.
09-23-03, 06:21 PM
#5
Eye In The Sky
iTrader: (2)
Join Date: Feb 2001
Location: In A Disfunctional World
Posts: 7,894
Likes: 0
Received 114 Likes
on
66 Posts
When you press the brakes you load down the alternator which loads the engine, all 100% normal.
Bouncing idles all almost 99% caused by too much air entering the throttle body. Adjust down your idle, you have two easy was to do that.
Be like Nike, just do it!
Bouncing idles all almost 99% caused by too much air entering the throttle body. Adjust down your idle, you have two easy was to do that.
Be like Nike, just do it!
09-23-03, 06:54 PM
#6
Belligerent MoFo
Being that I have very very very bad luck with alternators I can tell you that I have never had the rpms fluctuate at idle... unless it died. Test your battery. If the alt is going it'll start draining your battery if it's low it's a clue your alt maybe going.
Victor
Victor
09-23-03, 07:08 PM
#7
Call me gramps!
Thread Starter
Originally posted by cewrx7r1
When you press the brakes you load down the alternator which loads the engine, all 100% normal.
Bouncing idles all almost 99% caused by too much air entering the throttle body. Adjust down your idle, you have two easy was to do that.
Be like Nike, just do it!
When you press the brakes you load down the alternator which loads the engine, all 100% normal.
Bouncing idles all almost 99% caused by too much air entering the throttle body. Adjust down your idle, you have two easy was to do that.
Be like Nike, just do it!
Trending Topics
11-13-03, 09:36 AM
#9
Full Member
Join Date: Apr 2002
Location: Sweden
Posts: 192
Likes: 0
Received 0 Likes
on
0 Posts
Your EL-unit (Electrical Load) will tell the ECU when you hit the brakes, and your PS pressure switch will tell it when you turn the wheel. Both of these are input parameters for the idle control function of your ECU.
11-13-03, 05:06 PM
#10
Full Member
Join Date: Nov 2003
Location: CA
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
When you hit the brakes your brake booster uses the engine's vaccum and therefore the rpm will fluctuate. When you turn on the lights it puts a load on the electrical system which will cause the idle to fluctuate but it will settle back my understanding is that it's normal on all vehicles. When you turn the wheel your using the power steering pump which is driven off of the serpentine belt so the vehicle must compensate for it.
Last edited by mfigr1; 11-13-03 at 05:09 PM.
11-13-03, 08:39 PM
#11
Full Member
Join Date: Nov 2003
Location: Las Vegas
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
I have the same problem with my car , when I start it its at a high RPM until it warms up, then sometimes it will idle but seem to bounce up then down repeatedly... this only happens sometimes I messed with the air/fuel mixture and it doesnt happen no more...no electrical problems... nothing happens when I press brakes either...Im thinking its just the air flow in your car.
11-17-03, 02:47 AM
#13
Newbie
Join Date: Nov 2003
Location: Simi Valley, California
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by mfigr1
When you hit the brakes your brake booster uses the engine's vaccum and therefore the rpm will fluctuate. When you turn on the lights it puts a load on the electrical system which will cause the idle to fluctuate but it will settle back my understanding is that it's normal on all vehicles. When you turn the wheel your using the power steering pump which is driven off of the serpentine belt so the vehicle must compensate for it.
When you hit the brakes your brake booster uses the engine's vaccum and therefore the rpm will fluctuate. When you turn on the lights it puts a load on the electrical system which will cause the idle to fluctuate but it will settle back my understanding is that it's normal on all vehicles. When you turn the wheel your using the power steering pump which is driven off of the serpentine belt so the vehicle must compensate for it.
Thread
Thread Starter
Forum
Replies
Last Post
The1Sun
1st Generation Specific (1979-1985)
7
09-18-15 07:13 PM
The1Sun
1st Generation Specific (1979-1985)
0
09-07-15 10:21 PM
