so confused?
so confused? so today when i get to work i park my car and decide to leave it in gear instead of in nuetral. couple hours pass then i go out to my car start it up totally forgetting that i had left it in gear and took my foot of the clutch.. no biggie i think. then i go to start it again the bitch wouldnt start. so now im in he middle ghirradeli square at 1030 and i start to panic. i have no absolute power at all. the dam alarm wouldnt even go off. so i find someone who helps me try to jump the car. we hook up the jumpers and i get power to my car, go to start it and as soon as i turn the key to ignite it cuts the power.i dont know why because i just bought a new battery a week ago. so after about a half hour of frustration i decide to just get it towed. so now im sitting in my car and decide to go andcheck if the wire going to the battery was lose. turns out it was. so i tighten it as much as i could due to lack of tools. and i start it but this time with my foot on the gas. she starts right up but idles really low. i let it heat up but still idleing 200 below normal. so i take my hour drive home in complete stress, get home and grab a wrench and tighten the wire some more. starts up and struggles to idle still a little below normal. so i turn it of and back on and it idled normal. so i repeat the process a few time and every time it idled perfect. so could this just have been a loose wire, or should i be worried? or could this have something to do with the fact that i have a bad front o2 sensor? somebody please help so i can sleep at night. thanks
I just encountered a similar problem...after replacing an old batter myself with a crappy monkey wrench I did not have the battery cables tight enough. I was getting feedback and whining noise through the alternator/ac and after about a week of low charging due to the bad connection I couldn't get the car to start...I tried tightening the bolts to see if this was the problem and got the interior light to come on, but the engine would not turn over. I let the car sit for the night and in the morning I tried starting it again, succesfully. At first the idle was sporadic dropping very low, so I revved it for about 1-2 minutes, holding the idle up at 1200-1500. Then I turned it off, left it for 10 min. The next time it started up and idled fine, no problems since...about 3 weeks later. It sounds like you might have had the same problem, just see what happens for the next week, and make sure those bolts are extremely tight....The battery design on these GM's is very very crappy, the side mounted battery bolts are an inferior design for many reasons, this is one of them.
Launching!
Joined: Jan 2003
Posts: 238
Likes: 0
From: Apollo Beach, FL
Originally Posted by RFERG43
When the PCU loses power it has to re-learn and recalibrate all it's sensors. That is probably why the idle was a little off.
i reset my pcm once a couple years ago and when i started it, it almost stalled and sputtered for a little bit, but after a few minutes it was fine 
TECH Fanatic
Joined: May 2004
Posts: 1,030
Likes: 0
From: Wichita KS
thats odd, because when i completely replaced my car battery, my pcm did not have to relearn anything. It idled just fine. In fact when the chevy dealership replaced my pcm, it idled slightly high, but with in a minute it was back down to normal.... But my guess is in ur case the low voltage was not allowing some of the sensors to fully operate, or it caused them to send faulty readings and that may have effected your idle.
Staging Lane
Joined: Mar 2005
Posts: 95
Likes: 0
From: South Bay, CA
Originally Posted by RFERG43
When the PCU loses power it has to re-learn and recalibrate all it's sensors. That is probably why the idle was a little off.
