GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |

5.3 Extremely low idle

Old Feb 6, 2010 | 11:42 AM
  #21  
budhayes3's Avatar
PT's Slowest Truck
iTrader: (19)
 
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
Default

I doubt that the PCV is the problem, especially if it's only a year old. I have seen PCV's stick open, but that was only on vehicles that weren't properly maintained and the valve got full of sludge. If cleaning the IAC helped a little bit, even for a short period of time, I think you're on the right track.

Out of curiousity, how much was the IAC valve Lisa?
Reply
Old Feb 6, 2010 | 12:33 PM
  #22  
lady3bglover's Avatar
TECH Addict
iTrader: (3)
 
Joined: Dec 2006
Posts: 2,826
Likes: 0
From: Alvin, Texas
Default

Originally Posted by budhayes3
I doubt that the PCV is the problem, especially if it's only a year old. I have seen PCV's stick open, but that was only on vehicles that weren't properly maintained and the valve got full of sludge. If cleaning the IAC helped a little bit, even for a short period of time, I think you're on the right track.

Out of curiousity, how much was the IAC valve Lisa?
$35 on Ebay new, AC Delco.

I'm just getting frustrated. I've put a lot of money into my truck, and I'm unfortunately very proud of it....
Reply
Old Feb 6, 2010 | 12:43 PM
  #23  
1Bear's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Aug 2006
Posts: 1,410
Likes: 8
From: Jones Creek, Texas
Default

Lisa I know you said you've got the Haynes Bible, but just a little extra info:

Cleaning:
1) Do Not push or pull on the IAC valve pintle on IAC valves that have been in service. The force required to move the pintle may damage the threads on the worm drive.
2) Do Not soak the IAC valve in any liquid cleaner or solvent, as damage may result.

Installation:
1) Measure the distance between the tip of the IAC valve pintle and the mounting surface (1). If the distance is more than 28 mm (1.1 in) use finger pressure to slowly retract the pintle. The force required to retract the pintle of a new valve does not cause damage to the valve.
2) Lubricate the IAC valve O-ring with clean engine oil.
3) Install the IAC valve O-ring on the IAC valve.
4) Install the IAC valve.
5) Apply LOCTITE 262 to the IAC valve attaching screw threads if necessary.
6) Install the IAC valve screws. Tighten the screws to 3 N•m (27 lb in).
7) Plug in the IAC valve

Note: do not plug in the IAC valve and turn the key on before finishing the installation of the new valve.
Reply
Old Feb 6, 2010 | 12:48 PM
  #24  
lady3bglover's Avatar
TECH Addict
iTrader: (3)
 
Joined: Dec 2006
Posts: 2,826
Likes: 0
From: Alvin, Texas
Default

Bear...

I had followed all of the instructions up to putting Loctite and measuring the pounds of pressure....

I will just have to see when the new valve gets here. Thanks.
Reply
Old Feb 6, 2010 | 12:51 PM
  #25  
budhayes3's Avatar
PT's Slowest Truck
iTrader: (19)
 
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
Default

$35 sounds good for a factory part, hope it fixes your problem. My gut instinct tells me that it will
Reply
Old Feb 6, 2010 | 12:52 PM
  #26  
lady3bglover's Avatar
TECH Addict
iTrader: (3)
 
Joined: Dec 2006
Posts: 2,826
Likes: 0
From: Alvin, Texas
Default

Just let me know if I'm allowed to cry with the boys it it doesn't.
Reply
Old Feb 6, 2010 | 01:11 PM
  #27  
budhayes3's Avatar
PT's Slowest Truck
iTrader: (19)
 
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
Default

Originally Posted by lady3bglover
Just let me know if I'm allowed to cry with the boys it it doesn't.
Hopefully you'll be clapping instead..."there's no crying in auto repair"
Reply
Old Feb 8, 2010 | 08:36 PM
  #28  
lady3bglover's Avatar
TECH Addict
iTrader: (3)
 
Joined: Dec 2006
Posts: 2,826
Likes: 0
From: Alvin, Texas
Default

Ok, Billy we replaced both the IAC and the TPS. Now we wait till the morning.

Why the TPS, jic. I was reading the Haynes Bible and there was something in there that stuck out to me...
"A broken or loose TPS can cause intermittent bursts of fuel from the injectors and an unstable idle because the PCM thinks the throttle is moving."

What doesn't make any sense is the TPS literally looked new.
Reply
Old Feb 8, 2010 | 08:39 PM
  #29  
budhayes3's Avatar
PT's Slowest Truck
iTrader: (19)
 
Joined: Apr 2004
Posts: 17,863
Likes: 2
From: Hackensack, NJ
Default

I'm crossing my fingers for ya Lisa...I'm assuming that you inspected the wiring while you were in there also...
Reply
Old Feb 8, 2010 | 08:41 PM
  #30  
lady3bglover's Avatar
TECH Addict
iTrader: (3)
 
Joined: Dec 2006
Posts: 2,826
Likes: 0
From: Alvin, Texas
Default

Billy.. everything clips on. There wasn't anything that looked broken, torn, or loose.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TX Tahoe Z71
GMT 800 & Older GM General Discussion
9
Sep 1, 2015 09:11 PM
JordanH
GM Engine & Exhaust Performance
9
Aug 8, 2015 07:59 PM
Jake99
FORCED INDUCTION
18
Aug 8, 2015 07:56 AM
05GMC4.8
GMT 900 Trucks General Discussion
5
Aug 7, 2015 09:55 PM
OLD BULL
INTERNAL ENGINE MODIFICATIONS
13
Aug 1, 2015 05:00 PM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 11:28 PM.