Extremely strange stalling problem

[johnwc723]

Well I was driving about 180 miles back to school and on the last 20 miles I noticed my lights were getting really dim, the whole trip my battery light has been coming on and then going off but I hadn't had any troubles starting or running things.

Right about as it started to dim I noticed my engine begin to stall so I hit the accelerator. I figured this out pretty quick: the only way I could get my car to continue to run (not stalling) was to have the throttle pushed down a little/accelerating or else it just sputtered really hard (and I assume would stall). Oddly enough if I shift the car into neutral there were no apparent problems what so ever (and I didn't need to be pushing the accelerator)

Also a check engine light came on and its throwing 14 blinks (Idle Air Control Valve??) which doesn't really make sense. As I was driving my lights kept "dimming" but if I shifted to neutral it seemed that power was magically restored to full brightness, and I kept doing this to keep my lights from completely dying out.

I'm really confused, my alternator is only a few years old (~15,000mi) and it definitely wasn't doing this last time it failed, anything I'm overlooking?

[mix4]

I had this same problem with my Monte Carlo, I actually ended up stranded on the highway for about an hour until I figured it out. My issue was the power going into the fuse box was loose, so I tightened it and had no problems ever again. You're shorting out somewhere basically.

[Vanilla Sky]

Ok, are you dimming out at a stop, or while driving? If this is the case, then I'm sure that your computer is right, and that you need a new IACV.

[Estimated Prophet]

I'd try cleaning your IACV out, it's free and it may solve your problem.

[Blkblurr]

Nothing that was mentioned as a possible problem explains why his lights were dimming. My guess is you have a bad or loose alt belt that is sensitive to engine rpms. The fact that your batt light is coming on indicates your batt is not charging. You may have a corroded cable on your batt. or a corroded ot loose wire on your alt. It may be causing the computor to throw codes that may not be correct as well. Fix the charging problem first then see if the other problems are still there. BTW, when wires are shorting, it means they are touching both positive and negative usually resulting in a meltdown or blown fuse. Loose wires are just that. They are not shorting.

[Vanilla Sky]

Idling down to 200 RPM will cause the batt light to come on.

[Blkblurr]

Idling down to 200 RPM will cause the batt light to come on.
But not drain the battery. He was driving the car when this was happening. I doubt he was driving the car at 200 rpm.

[Vanilla Sky]

That's why I asked the question in my first post. Did this happen while moving, while taking off, while idleing? All of that is part of "driving" as a whole.

[johnwc723]

I'll check all that stuff, as far as the dimming it just happened when I was driving normally (at about 65 on the highway constant RPMs), the only way I could get the "power back" was to neutral the car. Perhaps this could be some slippage in the alternator belt at higher RPMs or something I suppose. I've had a lot of weird stuff happen with my car but this takes the cake, I'll keep you guys posted!

[Vanilla Sky]

Ok, now I'm in agreeance with BLk and yourself.

Make sure the alternator has both the hold down nut in place and the adjustment nut. I've had 3 adjustment nuts fall off on me, and they always caused a no charge condition. Beyond that, take your car to an Advance Auto. Have them test your charging system. You could have a voltage regulator going out.

Personally, I'd rather use a 200,000 mile OEM alt over a reman. The brushes and the bearings are all that are common wear items. Once, we pulled an OEM alt out of a 350,000 mile car. Greasebomb from hell that car was. The junkman didn't feel right even charging us for that alternator, so he just gave it to us. His loss. We had it tested, and it was great. The only thing we had to do was replace the brushes. Not a big deal at all.

[johnwc723]

Hmm, I'll have to check that as I did tighten the alternator belt before I drove (the reason being because it was squealing in the cold a lot) its so damn hard to figure out if I have the right "deflection" cause I don't have any official instruments to measure it.

[Estimated Prophet]

Nothing that was mentioned as a possible problem explains why his lights were dimming.

At low rpms the alternator wouldn't be putting out much, hence the dimming lights.

[Blkblurr]

At low rpms the alternator wouldn't be putting out much, hence the dimming lights. True but it's not what he said.

[Estimated Prophet]

I farted.