cold start hesitation
Thread Starter
Instructor
Joined: Jan 2010
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cold start hesitation
I have a 03 z06 with about 12k miles. So far my mod is a halltech venom intake.
When I start the car in the morning, it seems to turn over a lot more than normal. When I start the car when it's warm, it fires right up instantly and without hesitation. Any idea of what the issue might be?
Thanks
When I start the car in the morning, it seems to turn over a lot more than normal. When I start the car when it's warm, it fires right up instantly and without hesitation. Any idea of what the issue might be?
Thanks
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
What's your voltages in either condition?
Sounds like after sitting a bit and becoming cold soaked, the battery is becoming weak. When it's a restart, it's off a fresh charge.
Unless it's a condition where the engine turns over and over several revolutions before it fires, then you got other issues like fuel to look at. Have you pulled your DTCs to see if there are any relative?
Sounds like after sitting a bit and becoming cold soaked, the battery is becoming weak. When it's a restart, it's off a fresh charge.
Unless it's a condition where the engine turns over and over several revolutions before it fires, then you got other issues like fuel to look at. Have you pulled your DTCs to see if there are any relative?
Thread Starter
Instructor
Joined: Jan 2010
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Gas is fresh, as it's my dd. The issue seems to be recent. Voltage seems to be ok, since it reads at about 13 on a daily basis. Not sure if the starter is going for some reason. I bought the car with low mileage, but it's still an older car. I'm very new to Chevy's so I'm not familiar with any of the quirks.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Are you familiar with pulling the DTC codes?
If this battery is the original battery, then I'd be real suspicious it is telegraphing an impending situation for you.
If this battery is the original battery, then I'd be real suspicious it is telegraphing an impending situation for you.
Last edited by Jet-Jock; Jun 4, 2010 at 07:00 AM.
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
I would suggest to you, purchase a AC-Delco Professional 78-6YR/7YR Series battery. It's around $100 dollars and comes with a free replacement warranty for 30/50 months. It is the revised spec'd battery for this vehicle by Chevy. must have 120 reserve capacity.
Last edited by Jet-Jock; Aug 14, 2010 at 10:39 AM.
Tech Contributor
Joined: Jan 2004
Posts: 20,030
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From: Wylie TX --> Less is More, except under the hood !
Like others have said above....
I had the SAME issue as you are observing. I found that my battery readings on the dash were ok, but in fact my battery was weak. I replaced it and my car has been starting up quickly (like when it was new).
I had the SAME issue as you are observing. I found that my battery readings on the dash were ok, but in fact my battery was weak. I replaced it and my car has been starting up quickly (like when it was new).
Thread Starter
Instructor
Joined: Jan 2010
Posts: 106
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Dash gage readings do not tell you the state of health of the battery. With the engine running the dash gages reading is pretty much the output voltage of the alternator. Great to know it is working but tells you nothing about the health of the battery. With the key on and engine off the reading is pretty much meaningless since many circuits in the C5 are loading the battery. You need to know the voltage of the battery with no load on it. Measure the voltage directly across the battery terminals with a digital volt meter with no key in the ignition. If it's 12.5volts or less then the battery is low. Try charging it with a battery tender style charger. Once the battery is fully charged it should read between 12.7 and 12.9 volts. Disconnect the neg battery cable for at least overnight and remeasure the voltage the next morning. If it is back near 12.5 volts then the battery is on its way out as it does not hold a charge with no load attached. Alternatively have the battery load tested at your favorite parts store. Most do it free hoping they will sell you a battery if it doesn't show good.
That is all new info to me, and I definitely learned from it. I'll probably hit up the local parts store and have them test the battery as you mentioned.
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