PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

idle issue. help!!

Thread Tools
 
Search this Thread
 
Old Dec 10, 2012 | 12:02 PM
  #1  
cknoma2005's Avatar
Thread Starter
On The Tree
iTrader: (3)
 
Joined: Dec 2006
Posts: 160
Likes: 0
From: Houston, Tx
Default idle issue. help!!

My car will idle really low at times and sometime die when taking off in first gear well after it has warmed up. The car has a cam\tune and many other mods (listed in sig), It seems this may have started happening after I switched my pcv valve over from the old ball valve to the newer (ball less) orifice hole style. I know that sounds funny. I also changed from a flowmaster catback to a custom bullet style exhaust which is actually more free flowing. Now the car was tuned with an open cutout in the I-pipe. The cutout is no longer longer on the car. I don't think that is the issue because it would idle fine with the cutout closed flowing through the flowmaster catback.

Could it be the pcv change, o2 sensors(never been changed), exhaust, tune?
The car is throwing no codes and I had it scanned at Oreilly.

Any ideas would be helpful. Thanks.
Reply
Old Dec 11, 2012 | 11:40 AM
  #2  
blade2222's Avatar
TECH Apprentice
 
Joined: Jul 2007
Posts: 364
Likes: 0
Default

Try cleaning the throttle body first. Fixed a idle problem I was dealing with.
Reply
Old Dec 11, 2012 | 05:06 PM
  #3  
cknoma2005's Avatar
Thread Starter
On The Tree
iTrader: (3)
 
Joined: Dec 2006
Posts: 160
Likes: 0
From: Houston, Tx
Default

anyone??
Reply
Old Dec 11, 2012 | 05:08 PM
  #4  
cknoma2005's Avatar
Thread Starter
On The Tree
iTrader: (3)
 
Joined: Dec 2006
Posts: 160
Likes: 0
From: Houston, Tx
Default

Originally Posted by blade2222
Try cleaning the throttle body first. Fixed a idle problem I was dealing with.
throttle body blade appeared to be clean when I looked at it last, but I will check again.
Reply
Old Dec 11, 2012 | 05:14 PM
  #5  
cknoma2005's Avatar
Thread Starter
On The Tree
iTrader: (3)
 
Joined: Dec 2006
Posts: 160
Likes: 0
From: Houston, Tx
Default

If there is something wrong with my o2 sensors should they throw a code?
They appear to be the OEM style with vent(slots) on the end. I never replaced them. If they are the original o2 sensors and after 158,000 miles, one would think they wouldn't last that long. I don't have rear o2 sensors since I do not have cats. The rears were turned off when I had the car tuned.
Reply
Old Dec 11, 2012 | 08:06 PM
  #6  
blade2222's Avatar
TECH Apprentice
 
Joined: Jul 2007
Posts: 364
Likes: 0
Default

I'm surprised they have lasted that long, I would replace them just because there so old. They can't be operating very well. You'll probably notice a difference as well as some added fuel economy.
Reply
Old Dec 12, 2012 | 08:56 AM
  #7  
cknoma2005's Avatar
Thread Starter
On The Tree
iTrader: (3)
 
Joined: Dec 2006
Posts: 160
Likes: 0
From: Houston, Tx
Default

That is a good point, but I should note that I bought the car with 116,000 miles on the clock. I guess its possible they could have been replaced before I bought the car.

What is the average lifespan of o2 sensors? Which ones are good to buy besides oem?
NGK, Denso, Delphi, AC Delco?
Reply
Old Dec 12, 2012 | 09:30 AM
  #8  
edcmat-l1's Avatar
Banned
iTrader: (10)
 
Joined: Jul 2006
Posts: 4,782
Likes: 4
From: Va Beach
Default

Depending on the PCV setup, it can pull a significant amount of idle air through it. So yes, just changing the PCV can cause idle issues.

If you don't have any scanning/tuning software, you can try cracking the throttle blade, and then doing a TPS reset. Crack the blade a 1/4 turn on the screw, then unplug the TPS, and turn the key on. Wait 30 seconds. Turn the car off and plug the TPS back in. Test drive. If it's no better, crack the throttle blade another 1/4 turn on the screw, and repeat the TPS reset procedure. Basically what you're doing is getting the idle airflow back where it was with the original, higher flowing PCV valve.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Dec 12, 2012 | 09:56 AM
  #9  
cknoma2005's Avatar
Thread Starter
On The Tree
iTrader: (3)
 
Joined: Dec 2006
Posts: 160
Likes: 0
From: Houston, Tx
Default

Okay I will try that.

Its just weird. It idle fine most of the time, but sometimes when I let my foot off the throttle it will drop below 800rpms (normal idle) to like 400rpms or so. Then I have to rev it back up in order to correct it and keep if from dying. It does this the most at slow stop and go speeds like in parking lots or traffic.
Reply




All times are GMT -5. The time now is 06:02 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE