98 camaro cold idle problems

**lsruthles** · 12-08-2010, 06:21 AM

Hi everyone. I'm new to this forum and a first time owner of an ls-1. Having problems with my camaro idling at cold start-up. The only thing I have found is the tubing melted off the intake and pcv valve. I'm wondering if thats my problem and any advice would be more than welcome.

**konigandy6** · 12-08-2010, 06:33 AM

Welcome to LS1.com

Post your tech questions up the linked section, you'll get a lot more help there!

http://www.ls1.com/forums/forumdisplay.php?f=6

**lsruthles** · 12-08-2010, 06:36 AM

K. Thanx

**pajeff02** · 12-08-2010, 06:36 AM

A vacuum leak will generally cause a high idle issue. Other potential problems could be a dirty throttle body, a dirty or out of adjustment IAC valve on the side of the throttle body or a defective coolant temp sender. Other problems may also cause idle issues, but these are the most likely culprits. What are your symptoms?

And... Welcome!

**konigandy6** · 12-08-2010, 06:49 AM

Originally Posted by pajeff02

A vacuum leak will generally cause a high idle issue. Other potential problems could be a dirty throttle body, a dirty or out of adjustment IAC valve on the side of the throttle body or a defective coolant temp sender. Other problems may also cause idle issues, but these are the most likely culprits. What are your symptoms?

And... Welcome!

We just had an LS1 at the dealer with a high idle, turned out to be a leak at the intake manifold.

**lsruthles** · 12-08-2010, 06:51 AM

Symptoms as follows: Starts fine but idle jumps to 3000 rpm right away, then I have to feather the throttle as it drops to stall, if i catch it then it jumps back up to anywhere from 2000 to 3000 rpm and then dropps to stall again. cant apply any throttle or it will choke itself or overrev. After about five minutes of feathering the throttle it finally smooths out and runs fine till the engine gets cold again. I didnt know a faulty coolant level sensor could cause idle problems, but since you mentioned it, my coolant light comes on and goes off intermittantly since i bought the car.

**pajeff02** · 12-08-2010, 08:32 AM

The coolant temp sensor (not level sensor) controls closed and open loop operation. If the sensor was reading high it could cause an issue upon cold start up. Does not sound like that is your problem though from what you described.

**JayTA98** · 12-08-2010, 10:33 AM

I'll check and clean the throttle body. Check the IAC make sure is not getting stuck.

**0rion** · 12-08-2010, 11:32 AM

Originally Posted by lsruthles

Hi everyone. I'm new to this forum and a first time owner of an ls-1. Having problems with my camaro idling at cold start-up. The only thing I have found is the tubing melted off the intake and pcv valve. I'm wondering if thats my problem and any advice would be more than welcome.

describe this and have you fixed it? That will definitely cause a vacuum leak and could be your idle issues. If there's any air gettin into the intake via that vacuum hose that's your problem.

**0rion** · 12-08-2010, 11:34 AM

Originally Posted by pajeff02

The coolant temp sensor (not level sensor) controls closed and open loop operation. If the sensor was reading high it could cause an issue upon cold start up. Does not sound like that is your problem though from what you described.

the only time I've ever had an issue with a coolant temp sensor was on a buddies vette and it did exactly the opposite of this. It would start and run fine but as soon as it entered closed loop it would flood the car out.

**pajeff02** · 12-08-2010, 07:04 PM

Originally Posted by 0rion

the only time I've ever had an issue with a coolant temp sensor was on a buddies vette and it did exactly the opposite of this. It would start and run fine but as soon as it entered closed loop it would flood the car out.

Zapper had a bad coolant temp sensor on his '97 and it was causing idle issues similar to what the OP described -- and it ran rich, like you just said. Had I not heard of the similar problem, it would probably be one of the last things I would ever check on an idle issue.