Let's see if ya'll can explain this.

[4g63lover]

This happened twice this past week. The car is experiencing some charging system type failures. While idling the car will idle really low (close to 500 RPM) dropping the voltage shown by the voltmeter all the way down to almost 12 volts. It will feel like it is dying and the cluster lights will get bright once I rev it or once the IAC opens. I revved it once the first time and it stopped for the rest of the night. The second time, as I sat in traffic I had to play with the throttle keeping it above 1k-1.5k to keep the voltage from going too low. Eventually the voltage evened out at a steady 13.8-14.0 Volts read at the headunit (prolly a few volts off)

At first I thought it was the alternator but when I checked it with my DMM it read a solid 14.3 Volts while the car idled on the driveway @ 800(ish)rpm. No fluctuation.

So I went to the battery. Mind you, this battery is the battery thats been in the car since I have had it. I was for sure it was toast BUT with the car turned off the battery read 13.3V.

Now one thing that popped into my head is that maybe the car wasnt getting enough air when the plate is closed which caused the low idle. I dont have coolant lines running through the TB because I never used to drive the car in the winter. Could a small amount of icing (small enough to restrict but not enough to have the plate stick) cause the car to idle that low?

Any input will be appreciated. I love doing these diagnostic threads. We all learn something from it one way or another.

[Stewi]

The possibility of the the throttle plate being effected by the cold/icing etc. will always be a variable. I have never had coolant lines and it was never a problem for me personally but I would imagine mitsu put those lines there for a reason, I would make this your last resort because its probably the least common.

Take the battery out and have it tested at autozone or any place with a real battery tester. Many times a battery will show good voltage with a multimeter test but one any type of load is applied you will see its no good. That could be the whole problem or a contributing factor to the problem.

Double check all your ground wires in the engine bay, make sure none are loose or corroded, if possible, remove them, hit the metal with some sand paper and put electrical terminal grease on the connections.

I would do the simple stuff first like checking the battery, grounds, cleaning the ground points first and see what happens.

[RedGalant2k1]

I got a swank battery tester if you ever need it checked out. Other than that, double check any grounds leads that could have been damaged during the 5-speed swap. The rule I always use is inspect the most recent repairs or modifications first.

[mrg7243]

This sounds like what happened when a cell went bad in my battery.
Also check all of your connection points and ground for corrosion and cable splitting, and your battery terminals, when the battrey terminals crack they have a hard time providing current.

[4g63lover]

I've replaced the battery terminals due to a crack and all the grounds are where they are supposed to be. I will check the ground points and clean them up. I will also take the battery to be tested. It's pretty old. I'm pretty sure it's still the battery from the factory. none of my records show otherwise.

[Corey2kG]

Sorry for the off topic but what you recommend for a replacement for battery terminals. I got to mine suck.

[4g63lover]

I like the ones from napa. You unbolt the old terminals from the cables, then bolt the new ones on. Theyre nice and beefy.

[Corey2kG]

Link or pic please? Thanks.

[jimmy_o2]

i would double check the alty aswell, ive ran into exact symptoms when i had my corrola ohh and stay the heck away from delco altys

[jubeiaire]

i had the same issue with the g after i drained the life from my oem alt/battery. the cells in the battery would read proper voltage when in park-idle and alt would too but both were going bad and under full load(ingear) thats where the issue was. had the battery checked and it was 60% dead cells, enough to start me up but under load tha alt was doing all the work. changed the battery first, then 3 days latter alt went out cause it couldnt keep up with the new battery.

[4g63lover]

Started up the car today and found very little voltage fluctuation. I'm talking 14.65-14.67 while at idle. The volt meter from the headunit is also reading full voltage.

Going to get the battery tested as well as the alternator to see their health.

[oakrdrs187]

The possibility of the the throttle plate being effected by the cold/icing etc. will always be a variable. I have never had coolant lines and it was never a problem for me personally but I would imagine mitsu put those lines there for a reason, I would make this your last resort because its probably the least common.

Take the battery out and have it tested at autozone or any place with a real battery tester. Many times a battery will show good voltage with a multimeter test but one any type of load is applied you will see its no good. That could be the whole problem or a contributing factor to the problem.

Double check all your ground wires in the engine bay, make sure none are loose or corroded, if possible, remove them, hit the metal with some sand paper and put electrical terminal grease on the connections.

I would do the simple stuff first like checking the battery, grounds, cleaning the ground points first and see what happens.

X2
Autozone can load test while its in the car running.
And add to that once you have unplugged your battery, clean your TB real good, get you're fingers in there boy!!
http://i800.photobucket.com/albums/yy281/oakrdrs187/SHOCKER.gif

[4g63lover]

Got the battery checked. She's dead. I have no idea how she even cranked in this cold.

Voltage: 12.64V
Measured CCA: 224
Rated CCA: 525

So the battery might be the culprit. I am going to pull the alternator from the car and get that checked out as well.

[Galantman03]

It will feel like it is dying and the cluster lights will get bright once I rev it or once the IAC opens. I revved it once the first time and it stopped for the rest of the night.

now, i know your 5 speed swapped and you have a different tb too, i have the same problem, idles around 500 and even dies sometimes when i push in the clutch rolling to a stop sign. Could it be that your Idle Air Control Valve is bad? I assumed thats whats wrong with mine, since thats the only thing that i changed after the 5 speed swap. Or maybe its just because its cold in the winter. I guess idk, did it happen in the summer?

[4g63lover]

now, i know your 5 speed swapped and you have a different tb too, i have the same problem, idles around 500 and even dies sometimes when i push in the clutch rolling to a stop sign. Could it be that your Idle Air Control Valve is bad? I assumed thats whats wrong with mine, since thats the only thing that i changed after the 5 speed swap. Or maybe its just because its cold in the winter. I guess idk, did it happen in the summer?

Never happened in the summer. I already dealt with the IAC because I had the IAC malfunction code. It should be good and it is opening when the idle goes too low so I know it is functional. It's definitely charging system related.

[galantlvr34]

now, i know your 5 speed swapped and you have a different tb too, i have the same problem, idles around 500 and even dies sometimes when i push in the clutch rolling to a stop sign. Could it be that your Idle Air Control Valve is bad? I assumed thats whats wrong with mine, since thats the only thing that i changed after the 5 speed swap. Or maybe its just because its cold in the winter. I guess idk, did it happen in the summer?

you should have you battery and alternator tested as well and see if it is one or the other first.

[Stewi]

Got the battery checked. She's dead. I have no idea how she even cranked in this cold.

Voltage: 12.64V
Measured CCA: 224
Rated CCA: 525

So the battery might be the culprit. I am going to pull the alternator from the car and get that checked out as well.

Nice. I hate dead batteries, I chased my tail many times with my car to find out that my optima red top was dead.

[Galantman03]

you should have you battery and alternator tested as well and see if it is one or the other first.

I have a feeling its my alternator, but I'm not to worried about it, working on another motor

[galantlvr34]

I have a feeling its my alternator, but I'm not to worried about it, working on another motor

ok.yeah it probably is.you are rebuilding your motor?

[Galantman03]

^no, building a specific motor for turbo

[galantlvr34]

^no, building a specific motor for turbo

oh ok.

[4g63lover]

Alternator is dead as well. Wont even generate 10 amps. Going to deal with it after the new year.

[jimmy_o2]

i knew it well im glad u found out and remember stay away from A/C Delco