Delbert62

iTrader: (4)

I was tuning my car when it spontaneously developed a 2700 rpm idle. I went through all the usual suspects, vacuum leaks, MAF, MAP, IAC, cleaned the throttle body, checked the butterfly, checked the throttle linkage, every suggestion I could find on the forums. After many searches I found alot of people have had this problem and never posted what fixed it. Well the one thing that no one said to check was the battery voltage. Mine was at 12.2 volts but it was low enough to cause the idle to climb to the max. All it took was a good charging. I hope this helps someone sometime. Now can anyone tell me which field controls idle speed vs. system voltage?

Old Geezer

iTrader: (3)

Full charge is 12.6.. 12.2 wasn't low enuf to cause what U R reporting..
Did you get this 12.2 w/ engine off?
What was the alt putting out? @12.2, you should see some charge rate above that.
Engine/accessory loads would pull the volts down, if the alt is dead.

BTW, is this issue with your Yugo, or??

Jason454

Hey if it worked it worked. I will have to check my battery. I've got high idle.

Delbert62

iTrader: (4)

My Bad! I guess I assumed since this is a LS1 forum people would realize I was talking about an LS engine but here goes. This is a 2000 5.3 with a LS6 intake open air cleaner and short tube headers in a 68 Corvette. I am currently using a 98 Camaro ECU ( I have a 411 ECU on its way, been wanting to upgrade anyway).
I know it doesn't sound like the voltage should be low enough to cause problems,but that's all it took to fix it (after all the other stuff didn't work). I didn't check the alt output before charging. I wish I had now. I did notice the MIL is shut off for the system voltage in my tune. That will get turned back on.