badformulaLS1

iTrader: (1)

So this started happening rather recently. I think it is the battery but would like others opinions. Sometimes, but not always the car won't stay started for more than a few seconds. It just won't idle, almost like the battery doesn't have enough juice to keep it on cause I can rev the gas and keep the rpms at 1500-2000 and it'll stay on but if I let it drop it goes down to around 300-500 and wants to die on me. It does this for about 10 minutes and after that 10 minutes of driving it and keeping the rpms up above 1000 it goes back to normal and idles fine and drives fine and will start up fine for the next 5-6 start ups and then do it again. It's really strange. At that 300-500rpm idle it surges a bit as well, but only for a moment cause it'll either just shut off or I give it gas to keep it alive. It's even happened right after driving the car. I've been out driving around town for 20-30 mins (car started fine when I left the house) get back home, run inside and grab something and come out 5 mins later and it doesn't want to stay running. This is the main thing that has me worried that it's something worse than the battery. Possibly an issue with my tune? Or the alternator? I don't know but someone help please. The battery has also inexplicably died completely on me twice in the past month or so, and was able to be jumped both times but it took a while. The first time I took it to autozone and had it tested and the voltage was perfect, also the battery expired a year ago according to the sticker on it. But the voltage tested fine, and the gauge in my cluster looks good as well. Could it be an expired battery acting up? The car has also been going through belts. When I got the car it needed a new power steering pump. It was replaced along with the belt which eventually started to squeal. It was fine and a couple weeks later the squealing starts again. Replace belt and it's fine, a couple weeks later same thing. Maybe a bad idler pulley? I also hear a whine, similar to a supercharger whine but not quite. Mainly on acceleration from idle-2k rpm and past that the exhaust volume starts to cover it up but I'm sure it's still there. That just started happening a week or so ago, the same time that the belt started squealing after being replaced for the 3rd time.

BrainFreezE

iTrader: (2)

I had an issue like this before it was my negative battery cable was loose, also if the battery is disconnected for a while sometime it take a little for the car to re learn it's idle.
I had to drive it for a while then when i got home i slowly let of the gas till it stayed on by itself. if it wanted to turn off i added gas to keep it on then slowly let off again till it stayed on.

98TAProject

You could have a vacuum leak or a bad IAC when my iac got stuck mine did the same thing.

edit or with the squeal your bearings in the alternator could be going bad causing the battery not to charge or it could be as you say a bad battery.

fruitsalad

iTrader: (5)

Could be the alternator pulley. I would replace that battery first, but it's not likely to be causing it not to run. If it's starting fine, the battery is doing its job.

dailydriver

Our alternators (or generators, as the manual calls them), do start to make a blower type whine when they are going, or at least when the bearings are going.

Did you check your fuel pressure at the rail??

My car was doing something similar to this and it WAS the fuel pump, even though it started and ran for a few seconds.

badformulaLS1

iTrader: (1)

I've read some threads with people with the fuel pump issue and for those people giving it gas didn't work. The car would still die after a couple seconds. In my case I can give it gas and keep the rpms up above 1000 for 10 minutes or so and its fine after that. How would I check my fuel pressure? I'm gona try to have the car relearn its idle and check the battery cables, if that not it then I think it's either gota be the alternator, or idler pulley. I feel like the continuously failing belts are a big part of it.

I'll also look into the IAC or vacuum leak. Could a coolant temp sensor cause this? When my headers went in they broke the CTS. The car ran really really really crappy but didn't die like it does now but I've read that in some cases it has caused the car to die right on start up. I discovered this after the car had left the exhaust shop and was at another shop. I brought the guys there a new CTS, but they just gave it back to me and superglued the broken one together. I didn't say anything but it's worried me from time to time whenever I'm working in the engine bay and notice it. So I'll check that too. Thanks for the responses guys.

fruitsalad

iTrader: (5)

If it's eating belts too, I would definitely be looking at the alt first.

You can check fuel pressure by putting a gauge on the port on the rail. Any parts store will sell the gauge.